question

[rl@cs.unh.edu (Rongliang Li)]

Hi, here are some errors reported by TYPOL type-checking, I hope someone can
tell me why the incompatible types happened. I suppose types of IDENT and VALUE
are eventually strings. So, (string, SMALL::IDENT) should be compatible.


	Error: The variable V is used with incompatible types (string, SMALL::IDENT).
	Error: The variable N is used with incompatible types (string, SMALL::VALUE).

the errors came from the following typol rule:

	judgement	PAIR_S |- I, BOOL , B : PAIR_S ;
	pair_s[] |- ident V, false, num N: pair_s[pair(V, false, N)] ;

the corresponding parts of those in METAL file are:
	...

	pair_s  -> PAIR * ... ;
        pair    -> IDENT  BOOL VALUE ;

	...

        PAIRS   ::= pair_s ;
        PAIR    ::= pair ;
        VALUE   ::= num true false d_fun d_proc ;

	...

        <ident> ::= %ID ;
                ident-atom(%ID)
        <num>   ::= %INT ;
                num-atom(%INT)
	...

	ident   -> implemented as IDENTIFIER;
        num     -> implemented as STRING;

	IDENT ::= ident;
        B ::= num;

	...

Thank you.
			---Rongliang