-- Programming Language Technology Lab 4
-- "Fun": small untyped functional language

Prog.   Program ::= [Def] Main                     ;

DMain.  Main    ::= "main" "=" "print" Exp3 ";"    ;
DDef.   Def     ::= Ident [Ident] "=" Exp          ;

terminator Def ";"                                 ;

terminator Ident ""                                ;

EVar.   Exp3    ::= Ident                          ;
EInt.   Exp3    ::= Integer                        ;
EApp.   Exp2    ::= Exp2 Exp3                      ;
EAdd.   Exp1    ::= Exp1 "+" Exp2                  ;
ESub.   Exp1    ::= Exp1 "-" Exp2                  ;
ELt.    Exp1    ::= Exp1 "<" Exp2                  ;
EIf.    Exp     ::= "if" Exp "then" Exp "else" Exp ;
EAbs.   Exp     ::= "\\" Ident "->" Exp            ;

coercions Exp 3                                    ;

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