Program. Program ::= "main" "=" Exp ;

EId.  Exp3 ::= Ident   ;
EInt. Exp3 ::= Integer ;
EApp. Exp2 ::= Exp2 Exp3 ;
EAdd. Exp1 ::= Exp1 "+" Exp2 ;
EAbs. Exp  ::= "\\" Ident "->" Exp ;

coercions Exp 3 ;

comment "--" ;
comment "{-" "-}" ;