Compiler.Asttype ast = | Let of Types.ty * string * string list * ast * ast| LetRec of Types.ty * string * string list * ast * ast| App of Types.ty * string * ast list| Fun of Types.ty * string * ast| Sequence of Types.ty * ast list| IntLit of Types.ty * int| FloatLit of Types.ty * float| StringLit of Types.ty * string| BoolLit of Types.ty * bool| List of Types.ty * ast list| If of Types.ty * ast * ast * ast| Eq of Types.ty * ast * ast| Less of Types.ty * ast * ast| Greater of Types.ty * ast * ast| Plus of Types.ty * ast * ast| Minus of Types.ty * ast * ast| Times of Types.ty * ast * ast| Div of Types.ty * ast * ast| Cons of Types.ty * ast * ast| Append of Types.ty * ast * astval string_of_ast : ast -> string