fef4337e83
sets, maps and lists are now homogeneous. Lists by extension now require the "list" keyword, like sets and maps. Semicolons needed, instead of commas. New syntax for lists: `list [e_1; e_2; ...; e_n]`. The empty list can now be denoted either by `list []` or `list end` or `nil'. Both `list` and `nil` are new keywords. Lists can also be denoted without brackets, as sets and maps: `list e_1; e_2; ...; e_n end`. The extension for maps follows the extension for sets: `map [b_1; b_2; ...; b_n]` or `maps b_1; ...; b_n end`.