diff --git a/.gitignore b/.gitignore
index cf5ed1f94..fb756e969 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,4 @@
 /_build/
-dune-project
 *~
 *.merlin
 cache/*
@@ -7,4 +6,5 @@ Version.ml
 /_opam/
 /*.pp.ligo
 **/.DS_Store
-.vscode/
\ No newline at end of file
+.vscode/
+/ligo.install
diff --git a/dune-project b/dune-project
new file mode 100644
index 000000000..b3ec15752
--- /dev/null
+++ b/dune-project
@@ -0,0 +1,3 @@
+(lang dune 1.11)
+(name ligo)
+(using menhir 2.0)
diff --git a/src/bin/cli.ml b/src/bin/cli.ml
index b0a2c9251..edc0d9b44 100644
--- a/src/bin/cli.ml
+++ b/src/bin/cli.ml
@@ -66,7 +66,7 @@ let amount =
   let open Arg in
   let info =
     let docv = "AMOUNT" in
-    let doc = "$(docv) is the amount the dry-run transaction will use." in
+    let doc = "$(docv) is the amount the michelson interpreter will use." in
     info ~docv ~doc ["amount"] in
   value @@ opt string "0" info
 
@@ -74,7 +74,7 @@ let sender =
   let open Arg in
   let info =
     let docv = "SENDER" in
-    let doc = "$(docv) is the sender the dry-run transaction will use." in
+    let doc = "$(docv) is the sender the michelson interpreter transaction will use." in
     info ~docv ~doc ["sender"] in
   value @@ opt (some string) None info
 
@@ -82,10 +82,18 @@ let source =
   let open Arg in
   let info =
     let docv = "SOURCE" in
-    let doc = "$(docv) is the source the dry-run transaction will use." in
+    let doc = "$(docv) is the source the michelson interpreter transaction will use." in
     info ~docv ~doc ["source"] in
   value @@ opt (some string) None info
 
+let predecessor_timestamp =
+  let open Arg in
+  let info =
+    let docv = "PREDECESSOR_TIMESTAMP" in
+    let doc = "$(docv) is the pedecessor_timestamp the michelson interpreter transaction will use (e.g. '2000-01-01T10:10:10Z')" in
+    info ~docv ~doc ["predecessor-timestamp"] in
+  value @@ opt (some string) None info
+
 let display_format =
   let open Arg in
   let info  =
@@ -176,7 +184,7 @@ let compile_parameter =
   (Term.ret term , Term.info ~doc cmdname)
 
 let interpret =
-  let f expression init_file syntax amount sender source display_format =
+  let f expression init_file syntax amount sender source predecessor_timestamp display_format =
     toplevel ~display_format @@
     let%bind (decl_list,state,env) = match init_file with
       | Some init_file ->
@@ -192,13 +200,13 @@ let interpret =
     let%bind (typed_exp,_)     = Compile.Of_simplified.compile_expression ~env ~state simplified_exp in
     let%bind mini_c_exp        = Compile.Of_typed.compile_expression typed_exp in
     let%bind compiled_exp      = Compile.Of_mini_c.aggregate_and_compile_expression decl_list mini_c_exp in
-    let%bind options           = Run.make_dry_run_options {amount ; sender ; source } in
+    let%bind options           = Run.make_dry_run_options {predecessor_timestamp ; amount ; sender ; source } in
     let%bind value             = Run.run ~options compiled_exp.expr compiled_exp.expr_ty in
     let%bind simplified_output = Uncompile.uncompile_expression typed_exp.type_annotation value in
     ok @@ Format.asprintf "%a\n" Ast_simplified.PP.expression simplified_output
   in
   let term =
-    Term.(const f $ expression "EXPRESSION" 0 $ init_file $ syntax $ amount $ sender $ source $ display_format ) in
+    Term.(const f $ expression "EXPRESSION" 0 $ init_file $ syntax $ amount $ sender $ source $ predecessor_timestamp $ display_format ) in
   let cmdname = "interpret" in
   let doc = "Subcommand: interpret the expression in the context initialized by the provided source file." in
   (Term.ret term , Term.info ~doc cmdname)
@@ -233,7 +241,7 @@ let compile_storage =
   (Term.ret term , Term.info ~doc cmdname)
 
 let dry_run =
-  let f source_file entry_point storage input amount sender source syntax display_format =
+  let f source_file entry_point storage input amount sender source predecessor_timestamp syntax display_format =
     toplevel ~display_format @@
     let%bind simplified      = Compile.Of_source.compile source_file (Syntax_name syntax) in
     let%bind typed_prg,state = Compile.Of_simplified.compile simplified in
@@ -251,20 +259,20 @@ let dry_run =
     let%bind compiled_params   = Compile.Of_mini_c.compile_expression mini_c in
     let%bind args_michelson    = Run.evaluate_expression compiled_params.expr compiled_params.expr_ty in
 
-    let%bind options           = Run.make_dry_run_options {amount ; sender ; source } in
+    let%bind options           = Run.make_dry_run_options {predecessor_timestamp ; amount ; sender ; source } in
     let%bind michelson_output  = Run.run_contract ~options michelson_prg.expr michelson_prg.expr_ty args_michelson in
 
     let%bind simplified_output = Uncompile.uncompile_typed_program_entry_function_result typed_prg entry_point michelson_output in
     ok @@ Format.asprintf "%a\n" Ast_simplified.PP.expression simplified_output
   in
   let term =
-    Term.(const f $ source_file 0 $ entry_point 1 $ expression "PARAMETER" 2 $ expression "STORAGE" 3 $ amount $ sender $ source $ syntax $ display_format) in
+    Term.(const f $ source_file 0 $ entry_point 1 $ expression "PARAMETER" 2 $ expression "STORAGE" 3 $ amount $ sender $ source $ predecessor_timestamp $ syntax $ display_format) in
   let cmdname = "dry-run" in
   let doc = "Subcommand: run a smart-contract with the given storage and input." in
   (Term.ret term , Term.info ~doc cmdname)
 
 let run_function =
-  let f source_file entry_point parameter amount sender source syntax display_format =
+  let f source_file entry_point parameter amount sender source predecessor_timestamp syntax display_format =
     toplevel ~display_format @@
     let%bind v_syntax        = Helpers.syntax_to_variant (Syntax_name syntax) (Some source_file) in
     let%bind simplified_prg  = Compile.Of_source.compile source_file (Syntax_name syntax) in
@@ -278,32 +286,32 @@ let run_function =
     let%bind compiled_applied = Compile.Of_typed.compile_expression typed_app in
 
     let%bind michelson         = Compile.Of_mini_c.aggregate_and_compile_expression mini_c_prg compiled_applied in
-    let%bind options           = Run.make_dry_run_options {amount ; sender ; source } in
+    let%bind options           = Run.make_dry_run_options {predecessor_timestamp ; amount ; sender ; source } in
     let%bind michelson_output  = Run.run ~options michelson.expr michelson.expr_ty in
     let%bind simplified_output = Uncompile.uncompile_typed_program_entry_function_result typed_prg entry_point michelson_output in
     ok @@ Format.asprintf "%a\n" Ast_simplified.PP.expression simplified_output
   in
   let term =
-    Term.(const f $ source_file 0 $ entry_point 1 $ expression "PARAMETER" 2 $ amount $ sender $ source $ syntax $ display_format) in
+    Term.(const f $ source_file 0 $ entry_point 1 $ expression "PARAMETER" 2 $ amount $ sender $ source $ predecessor_timestamp $ syntax $ display_format) in
   let cmdname = "run-function" in
   let doc = "Subcommand: run a function with the given parameter." in
   (Term.ret term , Term.info ~doc cmdname)
 
 let evaluate_value =
-  let f source_file entry_point amount sender source syntax display_format =
+  let f source_file entry_point amount sender source predecessor_timestamp syntax display_format =
     toplevel ~display_format @@
     let%bind simplified        = Compile.Of_source.compile source_file (Syntax_name syntax) in
     let%bind typed_prg,_       = Compile.Of_simplified.compile simplified in
     let%bind mini_c            = Compile.Of_typed.compile typed_prg in
     let%bind (exp,_)           = Mini_c.get_entry mini_c entry_point in
     let%bind compiled          = Compile.Of_mini_c.aggregate_and_compile_expression mini_c exp in
-    let%bind options           = Run.make_dry_run_options {amount ; sender ; source } in
+    let%bind options           = Run.make_dry_run_options {predecessor_timestamp ; amount ; sender ; source } in
     let%bind michelson_output  = Run.run ~options compiled.expr compiled.expr_ty in
     let%bind simplified_output = Uncompile.uncompile_typed_program_entry_expression_result typed_prg entry_point michelson_output in
     ok @@ Format.asprintf "%a\n" Ast_simplified.PP.expression simplified_output
   in
   let term =
-    Term.(const f $ source_file 0 $ entry_point 1 $ amount $ sender $ source $ syntax $ display_format) in
+    Term.(const f $ source_file 0 $ entry_point 1 $ amount $ sender $ source $ predecessor_timestamp $ syntax $ display_format) in
   let cmdname = "evaluate-value" in
   let doc = "Subcommand: evaluate a given definition." in
   (Term.ret term , Term.info ~doc cmdname)
diff --git a/src/bin/expect_tests/help_tests.ml b/src/bin/expect_tests/help_tests.ml
index 9c8efcb6a..e804c8283 100644
--- a/src/bin/expect_tests/help_tests.ml
+++ b/src/bin/expect_tests/help_tests.ml
@@ -278,7 +278,7 @@ let%expect_test _ =
 
     OPTIONS
            --amount=AMOUNT (absent=0)
-               AMOUNT is the amount the dry-run transaction will use.
+               AMOUNT is the amount the michelson interpreter will use.
 
            --format=DISPLAY_FORMAT, --display-format=DISPLAY_FORMAT
            (absent=human-readable)
@@ -293,16 +293,22 @@ let%expect_test _ =
                `pager', `groff' or `plain'. With `auto', the format is `pager` or
                `plain' whenever the TERM env var is `dumb' or undefined.
 
+           --predecessor-timestamp=PREDECESSOR_TIMESTAMP
+               PREDECESSOR_TIMESTAMP is the pedecessor_timestamp the michelson
+               interpreter transaction will use (e.g. '2000-01-01T10:10:10Z')
+
            -s SYNTAX, --syntax=SYNTAX (absent=auto)
                SYNTAX is the syntax that will be used. Currently supported
                syntaxes are "pascaligo" and "cameligo". By default, the syntax is
                guessed from the extension (.ligo and .mligo, respectively).
 
            --sender=SENDER
-               SENDER is the sender the dry-run transaction will use.
+               SENDER is the sender the michelson interpreter transaction will
+               use.
 
            --source=SOURCE
-               SOURCE is the source the dry-run transaction will use.
+               SOURCE is the source the michelson interpreter transaction will
+               use.
 
            --version
                Show version information. |} ] ;
@@ -330,7 +336,7 @@ let%expect_test _ =
 
     OPTIONS
            --amount=AMOUNT (absent=0)
-               AMOUNT is the amount the dry-run transaction will use.
+               AMOUNT is the amount the michelson interpreter will use.
 
            --format=DISPLAY_FORMAT, --display-format=DISPLAY_FORMAT
            (absent=human-readable)
@@ -345,16 +351,22 @@ let%expect_test _ =
                `pager', `groff' or `plain'. With `auto', the format is `pager` or
                `plain' whenever the TERM env var is `dumb' or undefined.
 
+           --predecessor-timestamp=PREDECESSOR_TIMESTAMP
+               PREDECESSOR_TIMESTAMP is the pedecessor_timestamp the michelson
+               interpreter transaction will use (e.g. '2000-01-01T10:10:10Z')
+
            -s SYNTAX, --syntax=SYNTAX (absent=auto)
                SYNTAX is the syntax that will be used. Currently supported
                syntaxes are "pascaligo" and "cameligo". By default, the syntax is
                guessed from the extension (.ligo and .mligo, respectively).
 
            --sender=SENDER
-               SENDER is the sender the dry-run transaction will use.
+               SENDER is the sender the michelson interpreter transaction will
+               use.
 
            --source=SOURCE
-               SOURCE is the source the dry-run transaction will use.
+               SOURCE is the source the michelson interpreter transaction will
+               use.
 
            --version
                Show version information. |} ] ;
@@ -377,7 +389,7 @@ let%expect_test _ =
 
     OPTIONS
            --amount=AMOUNT (absent=0)
-               AMOUNT is the amount the dry-run transaction will use.
+               AMOUNT is the amount the michelson interpreter will use.
 
            --format=DISPLAY_FORMAT, --display-format=DISPLAY_FORMAT
            (absent=human-readable)
@@ -392,16 +404,22 @@ let%expect_test _ =
                `pager', `groff' or `plain'. With `auto', the format is `pager` or
                `plain' whenever the TERM env var is `dumb' or undefined.
 
+           --predecessor-timestamp=PREDECESSOR_TIMESTAMP
+               PREDECESSOR_TIMESTAMP is the pedecessor_timestamp the michelson
+               interpreter transaction will use (e.g. '2000-01-01T10:10:10Z')
+
            -s SYNTAX, --syntax=SYNTAX (absent=auto)
                SYNTAX is the syntax that will be used. Currently supported
                syntaxes are "pascaligo" and "cameligo". By default, the syntax is
                guessed from the extension (.ligo and .mligo, respectively).
 
            --sender=SENDER
-               SENDER is the sender the dry-run transaction will use.
+               SENDER is the sender the michelson interpreter transaction will
+               use.
 
            --source=SOURCE
-               SOURCE is the source the dry-run transaction will use.
+               SOURCE is the source the michelson interpreter transaction will
+               use.
 
            --version
                Show version information. |} ] ;
diff --git a/src/bin/expect_tests/typer_error_tests.ml b/src/bin/expect_tests/typer_error_tests.ml
index 5a407316f..6ecae91e7 100644
--- a/src/bin/expect_tests/typer_error_tests.ml
+++ b/src/bin/expect_tests/typer_error_tests.ml
@@ -1,11 +1,25 @@
 open Cli_expect
 
 let%expect_test _ =
-  run_ligo_bad [ "compile-contract" ; "../../test/contracts/error_typer_1.mligo" ; "foo" ] ;
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_1.mligo" ; "main" ] ;
   [%expect {| ligo: in file "error_typer_1.mligo", line 3, characters 19-27. different type constructors: Expected these two constant type constructors to be the same, but they're different {"a":"string","b":"int"} |} ] ;
 
-  run_ligo_bad [ "compile-contract" ; "../../test/contracts/error_typer_2.mligo" ; "foo" ] ;
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_2.mligo" ; "main" ] ;
   [%expect {| ligo: in file "error_typer_2.mligo", line 3, characters 24-39. different type constructors: Expected these two n-ary type constructors to be the same, but they're different {"a":"(TO_list(string))","b":"(TO_option(int))"} |} ] ;
 
-  (* run_ligo_bad [ "compile-contract" ; "../../test/contracts/error_typer_3.mligo" ; "foo" ] ;
-   * [%expect …some type error… ] ; *)
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_3.mligo" ; "main" ] ;
+  [%expect {| ligo: in file "error_typer_3.mligo", line 3, characters 34-53. tuples have different sizes: Expected these two types to be the same, but they're different (both are tuples, but with a different number of arguments) {"a":"tuple[int , string , bool]","b":"tuple[int , string]"} |} ] ;
+
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_4.mligo" ; "main" ] ;
+  [%expect {| ligo: in file "error_typer_4.mligo", line 4, characters 17-56. different keys in record:  {"key_a":"d","key_b":"c"} |} ] ;
+
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_5.mligo" ; "main" ] ;
+  [%expect {| ligo: unbound type variable:  {"variable":"boolean","in":"- E[]\tT[] ]","did_you_mean":"bool"} |} ] ;
+
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_6.mligo" ; "main" ] ;
+  [%expect {| ligo: in file "error_typer_6.mligo", line 1, characters 30-64. different type constructors: Expected these two constant type constructors to be the same, but they're different {"a":"string","b":"bool"} |} ] ;
+
+  run_ligo_bad [ "compile-contract" ; "../../test/contracts/negative/error_typer_7.mligo" ; "main" ] ;
+  [%expect {| ligo: in file "error_typer_7.mligo", line 4, characters 17-56. records have different sizes: Expected these two types to be the same, but they're different (both are records, but with a different number of arguments) {"a":"record[b -> string , a -> int]","b":"record[c -> bool , b -> string , a -> int]"} |} ] ;
+
+
diff --git a/src/main/display.ml b/src/main/display.ml
index da22fa883..991f7c2cc 100644
--- a/src/main/display.ml
+++ b/src/main/display.ml
@@ -1,4 +1,4 @@
-open! Trace
+open Trace
 
 let rec error_pp ?(dev = false) out (e : error) =
   let open JSON_string_utils in
diff --git a/src/main/run/of_michelson.ml b/src/main/run/of_michelson.ml
index ae2a2ea9f..ef26bc11a 100644
--- a/src/main/run/of_michelson.ml
+++ b/src/main/run/of_michelson.ml
@@ -16,6 +16,7 @@ type run_failwith_res =
 
 type dry_run_options =
   { amount : string ;
+    predecessor_timestamp : string option ;
     sender : string option ;
     source : string option }
 
@@ -44,7 +45,14 @@ let make_dry_run_options (opts : dry_run_options) : options result =
           (simple_error "invalid source address")
           (Contract.of_b58check source) in
       ok (Some source) in
-  ok @@ make_options ~amount ?source:sender ?payer:source ()
+  let%bind predecessor_timestamp =
+    match opts.predecessor_timestamp with
+    | None -> ok None
+    | Some st ->
+      match Memory_proto_alpha.Protocol.Alpha_context.Timestamp.of_notation st with
+        | Some t -> ok (Some t)
+        | None -> simple_fail ("\""^st^"\" is a bad timestamp notation") in
+  ok @@ make_options ?predecessor_timestamp:predecessor_timestamp ~amount ?source:sender ?payer:source ()
 
 let ex_value_ty_to_michelson (v : ex_typed_value) : Michelson.t result =
   let (Ex_typed_value (value , ty)) = v in
diff --git a/src/passes/1-parser/reasonligo.ml b/src/passes/1-parser/reasonligo.ml
index a3b52b110..260ddae3d 100644
--- a/src/passes/1-parser/reasonligo.ml
+++ b/src/passes/1-parser/reasonligo.ml
@@ -5,6 +5,73 @@ module AST = Parser_cameligo.AST
 module ParserLog = Parser_cameligo.ParserLog
 module LexToken = Parser_reasonligo.LexToken
 module Lexer = Lexer.Make(LexToken)
+module SyntaxError = Parser_reasonligo.SyntaxError
+
+module Errors = struct
+
+  let wrong_function_arguments expr =
+    let title () = "wrong function arguments" in
+    let message () = "" in
+    let expression_loc = AST.expr_to_region expr in
+    let data = [
+      ("expression_loc",
+       fun () -> Format.asprintf "%a" Location.pp_lift @@ expression_loc)
+    ] in
+    error ~data title message
+
+  let parser_error start end_ = 
+    let title () = "parser error" in
+    let message () = "" in    
+    let loc = Region.make 
+      ~start:(Pos.from_byte start) 
+      ~stop:(Pos.from_byte end_) 
+    in
+    let data = [
+      ("parser_loc", 
+        fun () -> Format.asprintf "%a" Location.pp_lift @@ loc
+      )      
+    ] in
+    error ~data title message
+  
+  let unrecognized_error start end_ = 
+    let title () = "unrecognized error" in
+    let message () = "" in
+    let loc = Region.make 
+      ~start:(Pos.from_byte start) 
+      ~stop:(Pos.from_byte end_) 
+    in
+    let data = [
+      ("unrecognized_loc", 
+        fun () -> Format.asprintf "%a" Location.pp_lift @@ loc
+      )      
+    ] in
+    error ~data title message
+
+end
+
+open Errors
+
+type 'a parser = (Lexing.lexbuf -> LexToken.token) -> Lexing.lexbuf -> 'a
+
+let parse (parser: 'a parser) lexbuf = 
+  let Lexer.{read ; close ; _} = Lexer.open_token_stream None in
+  let result = 
+    try
+      ok (parser read lexbuf)
+    with 
+      | SyntaxError.Error (WrongFunctionArguments e) -> 
+        fail @@ (wrong_function_arguments e)
+      | Parser.Error ->
+        let start = Lexing.lexeme_start_p lexbuf in
+        let end_ = Lexing.lexeme_end_p lexbuf in
+        fail @@ (parser_error start end_)
+      | _ ->
+        let start = Lexing.lexeme_start_p lexbuf in
+        let end_ = Lexing.lexeme_end_p lexbuf in
+        fail @@ (unrecognized_error start end_)          
+  in
+  close ();
+  result
 
 let parse_file (source: string) : AST.t result =  
   let pp_input =
@@ -20,104 +87,12 @@ let parse_file (source: string) : AST.t result =
     generic_try (simple_error "error opening file") @@
     (fun () -> open_in pp_input) in
   let lexbuf = Lexing.from_channel channel in
-  let Lexer.{read ; close ; _} =
-    Lexer.open_token_stream None in
-  specific_try (function      
-      | SyntaxError.Error WrongFunctionArguments -> 
-          let start = Lexing.lexeme_start_p lexbuf in
-          let end_ = Lexing.lexeme_end_p lexbuf in
-          let str = Format.sprintf
-              "Incorrect function arguments at \"%s\" from (%d, %d) to (%d, %d). In file \"%s|%s\"\n"
-              (Lexing.lexeme lexbuf)
-              start.pos_lnum (start.pos_cnum - start.pos_bol)
-              end_.pos_lnum (end_.pos_cnum - end_.pos_bol)
-              start.pos_fname source
-          in
-          simple_error str
-      | Parser.Error -> (
-          let start = Lexing.lexeme_start_p lexbuf in
-          let end_ = Lexing.lexeme_end_p lexbuf in
-          let str = Format.sprintf
-              "Parse error at \"%s\" from (%d, %d) to (%d, %d). In file \"%s|%s\"\n"
-              (Lexing.lexeme lexbuf)
-              start.pos_lnum (start.pos_cnum - start.pos_bol)
-              end_.pos_lnum (end_.pos_cnum - end_.pos_bol)
-              start.pos_fname source
-          in
-          simple_error str
-        )
-      | exn ->
-          let start = Lexing.lexeme_start_p lexbuf in
-          let end_ = Lexing.lexeme_end_p lexbuf in
-          let str = Format.sprintf
-              "Unrecognized error (%s) at \"%s\" from (%d, %d) to (%d, %d). In file \"%s|%s\"\n"
-              (Printexc.to_string exn)
-              (Lexing.lexeme lexbuf)
-              start.pos_lnum (start.pos_cnum - start.pos_bol)
-              end_.pos_lnum (end_.pos_cnum - end_.pos_bol)
-              start.pos_fname source
-          in
-          simple_error str
-    ) @@ (fun () ->
-      let raw = Parser.contract read lexbuf in
-      close () ;
-      raw
-    ) >>? fun raw ->
-  ok raw
+  parse (Parser.contract) lexbuf
 
 let parse_string (s:string) : AST.t result =
   let lexbuf = Lexing.from_string s in
-  let Lexer.{read ; close ; _} =
-    Lexer.open_token_stream None in
-  specific_try (function
-      | Parser.Error -> (
-          let start = Lexing.lexeme_start_p lexbuf in
-          let end_ = Lexing.lexeme_end_p lexbuf in
-          let str = Format.sprintf
-              "Parse error at \"%s\" from (%d, %d) to (%d, %d)\n"
-              (Lexing.lexeme lexbuf)
-              start.pos_lnum (start.pos_cnum - start.pos_bol)
-              end_.pos_lnum (end_.pos_cnum - end_.pos_bol) in
-          simple_error str
-        )
-      | _ -> simple_error "unrecognized parse_ error"
-    ) @@ (fun () ->
-      let raw = Parser.contract read lexbuf in
-      close () ;
-      raw
-    ) >>? fun raw ->
-  ok raw
+  parse (Parser.contract) lexbuf
 
 let parse_expression (s:string) : AST.expr result =
-  let lexbuf = Lexing.from_string s in
-  let Lexer.{read ; close; _} =
-    Lexer.open_token_stream None in
-  specific_try (function
-      | Parser.Error -> (
-          let start = Lexing.lexeme_start_p lexbuf in
-          let end_ = Lexing.lexeme_end_p lexbuf in
-          let str = Format.sprintf
-              "Parse error at \"%s\" from (%d, %d) to (%d, %d)\n"
-              (Lexing.lexeme lexbuf)
-              start.pos_lnum (start.pos_cnum - start.pos_bol)
-              end_.pos_lnum (end_.pos_cnum - end_.pos_bol) in
-          simple_error str
-        )
-      | exn ->
-          let start = Lexing.lexeme_start_p lexbuf in
-          let end_ = Lexing.lexeme_end_p lexbuf in
-          let str = Format.sprintf
-              "Unrecognized error (%s) at \"%s\" from (%d, %d) to (%d, %d). In expression \"%s|%s\"\n"
-              (Printexc.to_string exn)
-              (Lexing.lexeme lexbuf)
-              start.pos_lnum (start.pos_cnum - start.pos_bol)
-              end_.pos_lnum (end_.pos_cnum - end_.pos_bol)
-              start.pos_fname s
-          in
-          simple_error str
-    ) @@ (fun () ->
-      let raw = Parser.interactive_expr read lexbuf in
-      close () ;
-      raw
-    ) >>? fun raw ->
-  ok raw
+  let lexbuf = Lexing.from_string s in  
+  parse (Parser.interactive_expr) lexbuf
diff --git a/src/passes/1-parser/reasonligo/Parser.mly b/src/passes/1-parser/reasonligo/Parser.mly
index 444d12212..23deaf776 100644
--- a/src/passes/1-parser/reasonligo/Parser.mly
+++ b/src/passes/1-parser/reasonligo/Parser.mly
@@ -424,7 +424,7 @@ fun_expr:
           {p.value with inside = arg_to_pattern p.value.inside}
         in PPar {p with value}
     | EUnit u -> PUnit u
-    | _ -> raise (SyntaxError.Error WrongFunctionArguments)
+    | e -> raise (SyntaxError.Error (WrongFunctionArguments e))
     in
     let fun_args_to_pattern = function
       EAnnot {
@@ -453,7 +453,7 @@ fun_expr:
           in arg_to_pattern (fst fun_args), bindings
       | EUnit e ->
           arg_to_pattern (EUnit e), []
-      | _ -> raise (SyntaxError.Error WrongFunctionArguments)
+      | e -> raise (SyntaxError.Error (WrongFunctionArguments e))
     in
     let binders = fun_args_to_pattern $1 in
     let f = {kwd_fun;
diff --git a/src/passes/1-parser/shared/SyntaxError.ml b/src/passes/1-parser/reasonligo/SyntaxError.ml
similarity index 50%
rename from src/passes/1-parser/shared/SyntaxError.ml
rename to src/passes/1-parser/reasonligo/SyntaxError.ml
index a0faa0bbb..befbb27c2 100644
--- a/src/passes/1-parser/shared/SyntaxError.ml
+++ b/src/passes/1-parser/reasonligo/SyntaxError.ml
@@ -1,4 +1,4 @@
 type error = 
-  | WrongFunctionArguments
+  | WrongFunctionArguments of AST.expr
 
 exception Error of error
\ No newline at end of file
diff --git a/src/passes/1-parser/shared/SyntaxError.mli b/src/passes/1-parser/reasonligo/SyntaxError.mli
similarity index 50%
rename from src/passes/1-parser/shared/SyntaxError.mli
rename to src/passes/1-parser/reasonligo/SyntaxError.mli
index a0faa0bbb..befbb27c2 100644
--- a/src/passes/1-parser/shared/SyntaxError.mli
+++ b/src/passes/1-parser/reasonligo/SyntaxError.mli
@@ -1,4 +1,4 @@
 type error = 
-  | WrongFunctionArguments
+  | WrongFunctionArguments of AST.expr
 
 exception Error of error
\ No newline at end of file
diff --git a/src/passes/1-parser/reasonligo/dune b/src/passes/1-parser/reasonligo/dune
index fefe8c10e..f26008059 100644
--- a/src/passes/1-parser/reasonligo/dune
+++ b/src/passes/1-parser/reasonligo/dune
@@ -8,7 +8,7 @@
 (library
  (name parser_reasonligo)
  (public_name ligo.parser.reasonligo)
- (modules reasonligo LexToken Parser)
+ (modules SyntaxError reasonligo LexToken Parser)
  (libraries
    menhirLib
    parser_shared
diff --git a/src/passes/1-parser/reasonligo/reasonligo.ml b/src/passes/1-parser/reasonligo/reasonligo.ml
index e2cd732ea..48dd4401b 100644
--- a/src/passes/1-parser/reasonligo/reasonligo.ml
+++ b/src/passes/1-parser/reasonligo/reasonligo.ml
@@ -3,3 +3,4 @@ module AST = Parser_cameligo.AST
 module Lexer = Lexer
 module LexToken = LexToken
 module ParserLog = Parser_cameligo.ParserLog
+module SyntaxError = SyntaxError
diff --git a/src/passes/1-parser/shared/dune b/src/passes/1-parser/shared/dune
index 6756867ed..61c43fb28 100644
--- a/src/passes/1-parser/shared/dune
+++ b/src/passes/1-parser/shared/dune
@@ -15,8 +15,8 @@
     Markup
     FQueue
     EvalOpt
-    Version
-    SyntaxError))
+    Version  
+    ))
 
 
 (rule
diff --git a/src/passes/2-simplify/pascaligo.ml b/src/passes/2-simplify/pascaligo.ml
index ae96ddc27..6aea532e0 100644
--- a/src/passes/2-simplify/pascaligo.ml
+++ b/src/passes/2-simplify/pascaligo.ml
@@ -1,4 +1,4 @@
-open! Trace
+open Trace
 open Ast_simplified
 
 module Raw = Parser.Pascaligo.AST
diff --git a/src/passes/4-typer-new/typer.ml b/src/passes/4-typer-new/typer.ml
index 865461c58..f22dd61f9 100644
--- a/src/passes/4-typer-new/typer.ml
+++ b/src/passes/4-typer-new/typer.ml
@@ -54,7 +54,7 @@ module Errors = struct
 
   let match_redundant_case : type a . (a, unit) I.matching -> Location.t -> unit -> _ =
     fun matching loc () ->
-      let title = (thunk "missing case in match") in
+      let title = (thunk "redundant case in match") in
       let message () = "" in
       let data = [
         ("variant" , fun () -> Format.asprintf "%a" I.PP.matching_type matching) ;
diff --git a/src/passes/4-typer-old/typer.ml b/src/passes/4-typer-old/typer.ml
index 7792edcdb..b54b7e579 100644
--- a/src/passes/4-typer-old/typer.ml
+++ b/src/passes/4-typer-old/typer.ml
@@ -12,13 +12,20 @@ type environment = Environment.t
 
 module Errors = struct
   let unbound_type_variable (e:environment) (tv:I.type_variable) () =
+    let name = Var.to_name tv in
+    let suggestion = match name with
+        | "integer" -> "int"
+        | "str" -> "string"
+        | "boolean" -> "bool"
+        | _ -> "no suggestion" in
     let title = (thunk "unbound type variable") in
     let message () = "" in
     let data = [
       ("variable" , fun () -> Format.asprintf "%a" Stage_common.PP.type_variable tv) ;
       (* TODO: types don't have srclocs for now. *)
       (* ("location" , fun () -> Format.asprintf "%a" Location.pp (n.location)) ; *)
-      ("in" , fun () -> Format.asprintf "%a" Environment.PP.full_environment e)
+      ("in" , fun () -> Format.asprintf "%a" Environment.PP.full_environment e) ;
+      ("did_you_mean" , fun () -> suggestion)
     ] in
     error ~data title message ()
 
@@ -54,7 +61,7 @@ module Errors = struct
 
   let match_redundant_case : type a . (a, unit) I.matching -> Location.t -> unit -> _ =
     fun matching loc () ->
-    let title = (thunk "missing case in match") in
+    let title = (thunk "redundant case in match") in
     let message () = "" in
     let data = [
       ("variant" , fun () -> Format.asprintf "%a" I.PP.matching_type matching) ;
@@ -464,8 +471,6 @@ and type_expression' : environment -> ?tv_opt:O.type_value -> I.expression -> O.
         | None -> ok ()
         | Some tv' -> O.assert_type_value_eq (tv' , ae.type_annotation) in
       ok(ae)
-
-
   (* Sum *)
   | E_constructor (c, expr) ->
       let%bind (c_tv, sum_tv) =
@@ -793,7 +798,12 @@ and type_expression' : environment -> ?tv_opt:O.type_value -> I.expression -> O.
         (Some tv)
         (Some expr'.type_annotation)
         (internal_assertion_failure "merge_annotations (Some ...) (Some ...) failed") in
-    ok {expr' with type_annotation}
+    (* check type annotation of the expression as a whole (e.g. let x : t = (v : t') ) *)
+    let%bind () =
+      match tv_opt with
+      | None -> ok ()
+      | Some tv' -> O.assert_type_value_eq (tv' , type_annotation) in
+    ok @@ {expr' with type_annotation}
 
 
 and type_constant (name:I.constant) (lst:O.type_value list) (tv_opt:O.type_value option) : (O.constant * O.type_value) result =
diff --git a/src/passes/6-transpiler/transpiler.ml b/src/passes/6-transpiler/transpiler.ml
index dd967680e..916c7c88d 100644
--- a/src/passes/6-transpiler/transpiler.ml
+++ b/src/passes/6-transpiler/transpiler.ml
@@ -2,7 +2,7 @@
 
 For more info, see back-end.md: https://gitlab.com/ligolang/ligo/blob/dev/gitlab-pages/docs/contributors/big-picture/back-end.md *)
 
-open! Trace
+open Trace
 open Helpers
 
 module AST = Ast_typed
diff --git a/src/passes/6-transpiler/transpiler.mli b/src/passes/6-transpiler/transpiler.mli
index bebd4aa94..5defe6eba 100644
--- a/src/passes/6-transpiler/transpiler.mli
+++ b/src/passes/6-transpiler/transpiler.mli
@@ -1,4 +1,4 @@
-open! Trace
+open Trace
 
 module AST = Ast_typed
 module Append_tree = Tree.Append
diff --git a/src/passes/7-self_mini_c/self_mini_c.ml b/src/passes/7-self_mini_c/self_mini_c.ml
index cda2591a1..e025eed42 100644
--- a/src/passes/7-self_mini_c/self_mini_c.ml
+++ b/src/passes/7-self_mini_c/self_mini_c.ml
@@ -1,5 +1,5 @@
 open Mini_c
-open! Trace
+open Trace
 
 (* TODO hack to specialize map_expression to identity monad *)
 let map_expression :
diff --git a/src/passes/8-compiler/compiler_program.ml b/src/passes/8-compiler/compiler_program.ml
index 1c370b50a..37c44b7f3 100644
--- a/src/passes/8-compiler/compiler_program.ml
+++ b/src/passes/8-compiler/compiler_program.ml
@@ -29,8 +29,8 @@ open Errors
 (* This does not makes sense to me *)
 let get_operator : constant -> type_value -> expression list -> predicate result = fun s ty lst ->
   match Operators.Compiler.get_operators s with
-  | Trace.Ok (x,_) -> ok x
-  | Trace.Error _ -> (
+  | Ok (x,_) -> ok x
+  | Error _ -> (
       match s with
       | C_NONE -> (
           let%bind ty' = Mini_c.get_t_option ty in
@@ -452,4 +452,4 @@ and translate_function anon env input_ty output_ty : michelson result =
 type compiled_expression = {
   expr_ty : ex_ty ;
   expr : michelson ;
-}
\ No newline at end of file
+}
diff --git a/src/stages/ast_typed/misc.ml b/src/stages/ast_typed/misc.ml
index 4303a6f1b..ebfd7ee27 100644
--- a/src/stages/ast_typed/misc.ml
+++ b/src/stages/ast_typed/misc.ml
@@ -56,7 +56,7 @@ module Errors = struct
 
   let different_types name a b () =
     let title () = name ^ " are different" in
-    let message () = "" in
+    let message () = "Expected these two types to be the same, but they're different" in
     let data = [
       ("a" , fun () -> Format.asprintf "%a" PP.type_value a) ;
       ("b" , fun () -> Format.asprintf "%a" PP.type_value b )
@@ -321,7 +321,7 @@ let rec assert_type_value_eq (a, b: (type_value * type_value)) : unit result = m
       | TC_big_map (ka,va), TC_big_map (kb,vb) -> ok @@ ([ka;va] ,[kb;vb]) 
       | _,_ -> fail @@ different_operators opa opb
       in
-    trace (different_types "constant sub-expression" a b)
+    trace (different_types "arguments to type operators" a b)
       @@ bind_list_iter (fun (a,b) -> assert_type_value_eq (a,b) )(List.combine lsta lstb)
   )
   | T_operator _, _ -> fail @@ different_kinds a b
diff --git a/src/stages/common/PP.ml b/src/stages/common/PP.ml
index 411681a2a..05d192911 100644
--- a/src/stages/common/PP.ml
+++ b/src/stages/common/PP.ml
@@ -188,10 +188,14 @@ let literal ppf (l:literal) = match l with
   | Literal_timestamp n -> fprintf ppf "+%d" n
   | Literal_mutez n -> fprintf ppf "%dmutez" n
   | Literal_string s -> fprintf ppf "%S" s
-  | Literal_bytes b -> fprintf ppf "0x%s" @@ Bytes.to_string @@ Bytes.escaped b
+  | Literal_bytes b -> fprintf ppf "0x%a" Hex.pp (Hex.of_bytes b)
   | Literal_address s -> fprintf ppf "@%S" s
   | Literal_operation _ -> fprintf ppf "Operation(...bytes)"
   | Literal_key s      -> fprintf ppf "key %s" s
   | Literal_key_hash s -> fprintf ppf "key_hash %s" s
   | Literal_signature s -> fprintf ppf "Signature %s" s
   | Literal_chain_id s -> fprintf ppf "Chain_id %s" s
+
+let%expect_test _ =
+  Format.printf "%a" literal (Literal_bytes (Bytes.of_string "foo")) ;
+  [%expect{| 0x666f6f |}]
diff --git a/src/stages/common/dune b/src/stages/common/dune
index 35a886824..c607b6041 100644
--- a/src/stages/common/dune
+++ b/src/stages/common/dune
@@ -5,8 +5,9 @@
     simple-utils
     tezos-utils
   )
+  (inline_tests)
   (preprocess
-    (pps ppx_let)
+    (pps ppx_let ppx_expect)
   )
   (flags (:standard -open Simple_utils))
 )
diff --git a/src/stages/mini_c/PP.ml b/src/stages/mini_c/PP.ml
index 9e6ee6049..054d88cb9 100644
--- a/src/stages/mini_c/PP.ml
+++ b/src/stages/mini_c/PP.ml
@@ -58,8 +58,7 @@ let rec value ppf : value -> unit = function
   | D_unit -> fprintf ppf "unit"
   | D_string s -> fprintf ppf "\"%s\"" s
   | D_bytes x ->
-     let (`Hex hex) = Hex.of_bytes x in
-     fprintf ppf "0x%s" hex
+     fprintf ppf "0x%a" Hex.pp @@ Hex.of_bytes x
   | D_pair (a, b) -> fprintf ppf "(%a), (%a)" value a value b
   | D_left a -> fprintf ppf "L(%a)" value a
   | D_right b -> fprintf ppf "R(%a)" value b
@@ -124,6 +123,10 @@ let tl_statement ppf (ass, _) = assignment ppf ass
 let program ppf (p:program) =
   fprintf ppf "Program:\n---\n%a" (pp_print_list ~pp_sep:pp_print_newline tl_statement) p
 
+let%expect_test _ =
+  Format.printf "%a" value (D_bytes (Bytes.of_string "foo")) ;
+  [%expect{| 0x666f6f |}]
+
 let%expect_test _ =
   let pp = expression' Format.std_formatter in
   let dummy_type = T_base Base_unit in
diff --git a/src/test/contracts/error_typer_1.mligo b/src/test/contracts/error_typer_1.mligo
deleted file mode 100644
index b39f46dd9..000000000
--- a/src/test/contracts/error_typer_1.mligo
+++ /dev/null
@@ -1,3 +0,0 @@
-type toto = int
-
-let foo : string = 42 + 127
diff --git a/src/test/contracts/error_typer_2.mligo b/src/test/contracts/error_typer_2.mligo
deleted file mode 100644
index 77534fee2..000000000
--- a/src/test/contracts/error_typer_2.mligo
+++ /dev/null
@@ -1,3 +0,0 @@
-type toto = int option
-
-let foo : string list = Some (42 + 127)
diff --git a/src/test/contracts/negative/README b/src/test/contracts/negative/README
new file mode 100644
index 000000000..7e17f7aea
--- /dev/null
+++ b/src/test/contracts/negative/README
@@ -0,0 +1 @@
+This folder contains contracts for negative tests: contracts that are expected to fail (parse error, type error and so on).
diff --git a/src/test/contracts/negative/error_typer_1.mligo b/src/test/contracts/negative/error_typer_1.mligo
new file mode 100644
index 000000000..5baabe8c9
--- /dev/null
+++ b/src/test/contracts/negative/error_typer_1.mligo
@@ -0,0 +1,6 @@
+type toto = int
+
+let foo : string = 42 + 127
+
+let main (p:int) (storage : int) =
+  (([] : operation list) , p + foo)
diff --git a/src/test/contracts/negative/error_typer_2.mligo b/src/test/contracts/negative/error_typer_2.mligo
new file mode 100644
index 000000000..b8cf9d3cb
--- /dev/null
+++ b/src/test/contracts/negative/error_typer_2.mligo
@@ -0,0 +1,6 @@
+type toto = int option
+
+let foo : string list = Some (42 + 127)
+
+let main (p:int) (storage : int) =
+  (([] : operation list) , p)
diff --git a/src/test/contracts/error_typer_3.mligo b/src/test/contracts/negative/error_typer_3.mligo
similarity index 100%
rename from src/test/contracts/error_typer_3.mligo
rename to src/test/contracts/negative/error_typer_3.mligo
diff --git a/src/test/contracts/negative/error_typer_4.mligo b/src/test/contracts/negative/error_typer_4.mligo
new file mode 100644
index 000000000..a09820a8b
--- /dev/null
+++ b/src/test/contracts/negative/error_typer_4.mligo
@@ -0,0 +1,7 @@
+type toto = { a : int ; b : string ; c : bool }
+type tata = { a : int ; d : string ; c : bool }
+
+let foo : tata = ({a = 1 ; b = "foo" ; c = true} : toto)
+
+let main (p:int) (storage : int) =
+  (([] : operation list) , p + foo.a)
diff --git a/src/test/contracts/negative/error_typer_5.mligo b/src/test/contracts/negative/error_typer_5.mligo
new file mode 100644
index 000000000..942438933
--- /dev/null
+++ b/src/test/contracts/negative/error_typer_5.mligo
@@ -0,0 +1,4 @@
+let foo : boolean = 3
+
+let main (p:int) (storage : int) =
+  (([] : operation list) , p + foo)
diff --git a/src/test/contracts/negative/error_typer_6.mligo b/src/test/contracts/negative/error_typer_6.mligo
new file mode 100644
index 000000000..d885cd036
--- /dev/null
+++ b/src/test/contracts/negative/error_typer_6.mligo
@@ -0,0 +1,3 @@
+let foo : (int, string) map = (Map.literal [] : (int, bool) map)
+let main (p:int) (storage : int) =
+  (([] : operation list) , p)
diff --git a/src/test/contracts/negative/error_typer_7.mligo b/src/test/contracts/negative/error_typer_7.mligo
new file mode 100644
index 000000000..00243b095
--- /dev/null
+++ b/src/test/contracts/negative/error_typer_7.mligo
@@ -0,0 +1,7 @@
+type toto = { a : int ; b : string }
+type tata = { a : int ; }
+
+let foo : tata = ({a = 1 ; b = "foo" ; c = true} : toto)
+
+let main (p:int) (storage : int) =
+  (([] : operation list) , p + foo.a)
diff --git a/src/test/contracts/time-lock.ligo b/src/test/contracts/time-lock.ligo
new file mode 100644
index 000000000..c45f40a23
--- /dev/null
+++ b/src/test/contracts/time-lock.ligo
@@ -0,0 +1,25 @@
+type storage_t is timestamp
+
+type message_t is (unit -> list(operation))
+type default_pt is unit
+type call_pt is message_t
+type contract_return_t is (list(operation) * storage_t)
+
+type entry_point_t is
+| Call of call_pt
+| Default of default_pt
+
+function call (const p : call_pt; const s : storage_t) : contract_return_t is block {
+  if s >= now then failwith("Contract is still time locked") else skip ;
+  const message : message_t = p ;
+  const ret_ops : list(operation) = message(unit) ;
+} with (ret_ops,s)
+
+function default (const p : default_pt; const s : storage_t) : contract_return_t is
+  ((nil: list(operation)) , s)
+
+function main(const param : entry_point_t; const s : storage_t) : contract_return_t is 
+  case param of
+  | Call     (p) -> call(p,s)
+  | Default  (p) -> default(p,s)
+end
\ No newline at end of file
diff --git a/src/test/dune b/src/test/dune
index 8d32a8624..24a44109f 100644
--- a/src/test/dune
+++ b/src/test/dune
@@ -15,7 +15,8 @@
 (alias
   (name ligo-test)
   (action (run ./test.exe))
-  (deps (glob_files contracts/*))
+  (deps (glob_files contracts/*)
+        (glob_files contracts/negative/*))
 )
 
 (alias
diff --git a/src/test/test.ml b/src/test/test.ml
index b1cafc9cf..b63e1ad5f 100644
--- a/src/test/test.ml
+++ b/src/test/test.ml
@@ -13,5 +13,6 @@ let () =
     Multisig_tests.main ;
     Multisig_v2_tests.main ;
     Replaceable_id_tests.main ;
+    Time_lock_tests.main ;
   ] ;
   ()
diff --git a/src/test/test_helpers.ml b/src/test/test_helpers.ml
index 5c3e6d771..928e828e8 100644
--- a/src/test/test_helpers.ml
+++ b/src/test/test_helpers.ml
@@ -1,4 +1,4 @@
-open! Trace
+open Trace
 
 type test_case = unit Alcotest.test_case
 type test =
@@ -17,7 +17,7 @@ let wrap_test name f =
 
 let wrap_test_raw f =
   match f () with
-  | Trace.Ok ((), annotations) -> ignore annotations; ()
+  | Ok ((), annotations) -> ignore annotations; ()
   | Error err ->
     Format.printf "%a\n%!" (Ligo.Display.error_pp ~dev:true) (err ())
 
diff --git a/src/test/time_lock_tests.ml b/src/test/time_lock_tests.ml
new file mode 100644
index 000000000..83830b11f
--- /dev/null
+++ b/src/test/time_lock_tests.ml
@@ -0,0 +1,69 @@
+open Trace
+open Test_helpers
+
+let type_file f = 
+  let%bind simplified  = Ligo.Compile.Of_source.compile f (Syntax_name "pascaligo") in
+  let%bind typed,state = Ligo.Compile.Of_simplified.compile simplified in
+  ok @@ (typed,state)
+
+let get_program =
+  let s = ref None in
+  fun () -> match !s with
+    | Some s -> ok s
+    | None -> (
+        let%bind program = type_file "./contracts/time-lock.ligo" in
+        s := Some program ;
+        ok program
+      )
+
+let compile_main () = 
+  let%bind simplified      = Ligo.Compile.Of_source.compile "./contracts/time-lock.ligo" (Syntax_name "pascaligo") in
+  let%bind typed_prg,_ = Ligo.Compile.Of_simplified.compile simplified in
+  let%bind mini_c_prg      = Ligo.Compile.Of_typed.compile typed_prg in
+  let%bind michelson_prg   = Ligo.Compile.Of_mini_c.aggregate_and_compile_contract mini_c_prg "main" in
+  let%bind (_contract: Tezos_utils.Michelson.michelson) =
+    (* fails if the given entry point is not a valid contract *)
+    Ligo.Compile.Of_michelson.build_contract michelson_prg in
+  ok ()
+
+open Ast_simplified
+let empty_op_list = 
+  (e_typed_list [] t_operation)
+let empty_message = e_lambda (Var.of_name "arguments")
+  (Some t_unit) (Some (t_list t_operation))
+  empty_op_list
+
+let call msg = e_constructor "Call" msg
+let mk_time st = 
+  match Memory_proto_alpha.Protocol.Alpha_context.Timestamp.of_notation st with
+  | Some s -> ok s
+  | None -> simple_fail "bad timestamp notation"
+let to_sec t = Tezos_utils.Time.Protocol.to_seconds t
+let storage st = e_timestamp (Int64.to_int @@ to_sec st)
+
+let early_call () =
+  let%bind program,_ = get_program () in
+  let%bind predecessor_timestamp = mk_time "2000-01-01T00:10:10Z" in
+  let%bind lock_time = mk_time "2000-01-01T10:10:10Z" in
+  let init_storage = storage lock_time in
+  let options =
+    Proto_alpha_utils.Memory_proto_alpha.make_options ~predecessor_timestamp () in
+  let exp_failwith = "Contract is still time locked" in
+  expect_string_failwith ~options program "main"
+    (e_pair (call empty_message)  init_storage) exp_failwith
+
+let call_on_time () =
+  let%bind program,_ = get_program () in
+  let%bind predecessor_timestamp = mk_time "2000-01-01T10:10:10Z" in
+  let%bind lock_time = mk_time "2000-01-01T00:10:10Z" in
+  let init_storage = storage lock_time in
+  let options =
+    Proto_alpha_utils.Memory_proto_alpha.make_options ~predecessor_timestamp () in
+  expect_eq ~options program "main"
+    (e_pair (call empty_message) init_storage) (e_pair empty_op_list init_storage)
+
+let main = test_suite "Time lock" [
+    test "compile" compile_main ;
+    test "early call" early_call ;
+    test "call on time" call_on_time ;
+  ]
\ No newline at end of file
diff --git a/vendors/ligo-utils/memory-proto-alpha/dune-project b/vendors/ligo-utils/memory-proto-alpha/dune-project
new file mode 100644
index 000000000..1cf86c9fe
--- /dev/null
+++ b/vendors/ligo-utils/memory-proto-alpha/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name tezos-memory-proto-alpha)
diff --git a/vendors/ligo-utils/proto-alpha-utils/dune-project b/vendors/ligo-utils/proto-alpha-utils/dune-project
new file mode 100644
index 000000000..45c9397fd
--- /dev/null
+++ b/vendors/ligo-utils/proto-alpha-utils/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name proto-alpha-utils)
diff --git a/vendors/ligo-utils/proto-alpha-utils/trace.ml b/vendors/ligo-utils/proto-alpha-utils/trace.ml
index 812ce0405..54bf77db3 100644
--- a/vendors/ligo-utils/proto-alpha-utils/trace.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/trace.ml
@@ -11,7 +11,7 @@ let of_alpha_tz_error err = of_tz_error (AE.Ecoproto_error err)
 
 let trace_alpha_tzresult err : 'a AE.Error_monad.tzresult -> 'a result =
   function
-  | Result.Ok x -> ok x
+  | Ok x -> ok x
   | Error errs -> fail @@ thunk @@ patch_children (List.map of_alpha_tz_error errs) (err ())
 
 let trace_alpha_tzresult_lwt error (x:_ AE.Error_monad.tzresult Lwt.t) : _ result =
@@ -19,17 +19,17 @@ let trace_alpha_tzresult_lwt error (x:_ AE.Error_monad.tzresult Lwt.t) : _ resul
 
 let trace_tzresult err =
   function
-  | Result.Ok x -> ok x
+  | Ok x -> ok x
   | Error errs -> fail @@ thunk @@ patch_children (List.map of_tz_error errs) (err ())
 
 (* TODO: should be a combination of trace_tzresult and trace_r *)
 let trace_tzresult_r err_thunk_may_fail =
   function
-  | Result.Ok x -> ok x
+  | Ok x -> ok x
   | Error errs ->
       let tz_errs = List.map of_tz_error errs in
       match err_thunk_may_fail () with
-      | Simple_utils.Trace.Ok (err, annotations) ->
+      | Ok (err, annotations) ->
          ignore annotations ;
          Error (fun () -> patch_children tz_errs (err ()))
       | Error errors_while_generating_error ->
diff --git a/vendors/ligo-utils/proto-alpha-utils/x_memory_proto_alpha.ml b/vendors/ligo-utils/proto-alpha-utils/x_memory_proto_alpha.ml
index 460494379..d47b85086 100644
--- a/vendors/ligo-utils/proto-alpha-utils/x_memory_proto_alpha.ml
+++ b/vendors/ligo-utils/proto-alpha-utils/x_memory_proto_alpha.ml
@@ -1066,13 +1066,16 @@ type options = {
 
 let make_options
     ?(tezos_context = dummy_environment.tezos_context)
+    ?(predecessor_timestamp = dummy_environment.tezos_context.predecessor_timestamp)
     ?(source = (List.nth dummy_environment.identities 0).implicit_contract)
     ?(self = (List.nth dummy_environment.identities 0).implicit_contract)
     ?(payer = (List.nth dummy_environment.identities 1).implicit_contract)
     ?(amount = Alpha_context.Tez.one)
     ?(chain_id = Environment.Chain_id.zero)
     ()
-  = {
+  =
+  let tezos_context = { tezos_context with predecessor_timestamp } in
+  {
     tezos_context ;
     source ;
     self ;
diff --git a/vendors/ligo-utils/simple-utils/dune-project b/vendors/ligo-utils/simple-utils/dune-project
new file mode 100644
index 000000000..f33d41d33
--- /dev/null
+++ b/vendors/ligo-utils/simple-utils/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name simple-utils)
diff --git a/vendors/ligo-utils/simple-utils/trace.ml b/vendors/ligo-utils/simple-utils/trace.ml
index 7464d8fb1..dc80894d4 100644
--- a/vendors/ligo-utils/simple-utils/trace.ml
+++ b/vendors/ligo-utils/simple-utils/trace.ml
@@ -6,8 +6,8 @@
 *)
 
 module Trace_tutorial = struct
-  (** The trace monad is fairly similar to the predefined option
-      type. *)
+  (** The trace monad is fairly similar to the predefined [option]
+      type. It is an instance of the predefined [result] type. *)
 
   type annotation = string
   type      error = string
@@ -23,18 +23,20 @@ module Trace_tutorial = struct
       list of annotations (information about past successful
       computations), or it is a list of errors accumulated so far.
       The former case is denoted by the data constructor [Ok], and the
-      second by [Errors].
+      second by [Error].
    *)
-  type 'a result =
-    Ok of 'a * annotation list
-  | Errors of error list
+  type nonrec 'a result = ('a * annotation list, error list) result
+  (*
+  = Ok of 'a * annotation list
+  | Error of error list
+  *)
 
   (** The function [divide_trace] shows the basic use of the trace
       monad.
    *)
   let divide_trace a b =
     if   b = 0
-    then Errors [Printf.sprintf "division by zero: %d/%d" a b]
+    then Error [Printf.sprintf "division by zero: %d/%d" a b]
     else Ok (a/b, [])
 
   (** The function [divide_three] shows that when composing two
@@ -81,7 +83,7 @@ module Trace_tutorial = struct
         match f x with
           Ok (x', annot') -> Ok (x', annot' @ annot)
         |          errors -> ignore annot; errors)
-    | Errors _ as e -> e
+    | Error _ as e -> e
 
   (** The function [divide_three_bind] is equivalent to the verbose
       [divide_three] above, but makes use of [bind].
@@ -169,7 +171,7 @@ module Trace_tutorial = struct
         {li If the list only contains [Ok] values, it strips the [Ok]
          of each element and returns that list wrapped with [Ok].}
         {li Otherwise, one or more of the elements of the input list
-         is [Errors], then [bind_list] returns the first error in the
+         is [Error], then [bind_list] returns the first error in the
          list.}}
    *)
   let rec bind_list = function
@@ -199,7 +201,7 @@ module Trace_tutorial = struct
         And this will pass along the error triggered by [get key map].
    *)
   let trace err = function
-    Errors e -> Errors (err::e)
+    Error e -> Error (err::e)
   | ok -> ok
 
   (** The real trace monad is very similar to the one that we have
@@ -293,9 +295,11 @@ type annotation_thunk = annotation thunk
 (** Types of traced elements. It might be good to rename it [trace] at
     some point.
  *)
-type 'a result =
-  Ok    of 'a * annotation_thunk list
+type nonrec 'a result = ('a * annotation_thunk list, error_thunk) result
+(*
+= Ok    of 'a * annotation_thunk list
 | Error of error_thunk
+*)
 
 
 (** {1 Constructors} *)
diff --git a/vendors/ligo-utils/tezos-protocol-alpha-parameters/dune-project b/vendors/ligo-utils/tezos-protocol-alpha-parameters/dune-project
new file mode 100644
index 000000000..6910ef322
--- /dev/null
+++ b/vendors/ligo-utils/tezos-protocol-alpha-parameters/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name tezos-protocol-005-PsBabyM1-parameters)
diff --git a/vendors/ligo-utils/tezos-protocol-alpha/alpha_context.mli b/vendors/ligo-utils/tezos-protocol-alpha/alpha_context.mli
index b970ad110..73dcb59ea 100644
--- a/vendors/ligo-utils/tezos-protocol-alpha/alpha_context.mli
+++ b/vendors/ligo-utils/tezos-protocol-alpha/alpha_context.mli
@@ -30,7 +30,7 @@ module type BASIC_DATA = sig
   val pp: Format.formatter -> t -> unit
 end
 
-type t
+type t = Raw_context.t
 type context = t
 
 type public_key = Signature.Public_key.t
diff --git a/vendors/ligo-utils/tezos-protocol-alpha/dune-project b/vendors/ligo-utils/tezos-protocol-alpha/dune-project
new file mode 100644
index 000000000..d4d600dc7
--- /dev/null
+++ b/vendors/ligo-utils/tezos-protocol-alpha/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name tezos-embedded-protocol-005-PsBabyM1)
diff --git a/vendors/ligo-utils/tezos-protocol-alpha/raw_context.mli b/vendors/ligo-utils/tezos-protocol-alpha/raw_context.mli
index 86cc62187..749878b6c 100644
--- a/vendors/ligo-utils/tezos-protocol-alpha/raw_context.mli
+++ b/vendors/ligo-utils/tezos-protocol-alpha/raw_context.mli
@@ -45,7 +45,34 @@ val storage_error: storage_error -> 'a tzresult Lwt.t
 (** Abstract view of the context.
     Includes a handle to the functional key-value database
     ({!Context.t}) along with some in-memory values (gas, etc.). *)
-type t
+module Int_set : sig
+  type t
+end
+type t = {
+  context: Context.t ;
+  constants: Constants_repr.parametric ;
+  first_level: Raw_level_repr.t ;
+  level: Level_repr.t ;
+  predecessor_timestamp: Time.t ;
+  timestamp: Time.t ;
+  fitness: Int64.t ;
+  deposits: Tez_repr.t Signature.Public_key_hash.Map.t ;
+  included_endorsements: int ;
+  allowed_endorsements:
+    (Signature.Public_key.t * int list * bool) Signature.Public_key_hash.Map.t ;
+  fees: Tez_repr.t ;
+  rewards: Tez_repr.t ;
+  block_gas: Z.t ;
+  operation_gas: Gas_limit_repr.t ;
+  internal_gas: Gas_limit_repr.internal_gas ;
+  storage_space_to_pay: Z.t option ;
+  allocated_contracts: int option ;
+  origination_nonce: Contract_repr.origination_nonce option ;
+  temporary_big_map: Z.t ;
+  internal_nonce: int ;
+  internal_nonces_used: Int_set.t ;
+}
+
 type context = t
 type root_context = t
 
diff --git a/vendors/ligo-utils/tezos-utils/dune-project b/vendors/ligo-utils/tezos-utils/dune-project
new file mode 100644
index 000000000..d08be9590
--- /dev/null
+++ b/vendors/ligo-utils/tezos-utils/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name tezos-utils)
diff --git a/vendors/ligo-utils/tezos-utils/michelson-parser/dune-project b/vendors/ligo-utils/tezos-utils/michelson-parser/dune-project
new file mode 100644
index 000000000..9b32caac7
--- /dev/null
+++ b/vendors/ligo-utils/tezos-utils/michelson-parser/dune-project
@@ -0,0 +1,2 @@
+(lang dune 1.11)
+(name michelson-parser)