[polyml] InternalError: Equality for function raised

David, David,

Using recent sources, the following caused an internal error as described in the comment. The problem persists when I update to the very latest (rev. 866).

fun present (eq : ('a * 'a) -> bool) (x: 'a) : 'a list -> bool = ( let fun test (h :: t) = eq(x,h) orelse test t | test [] = false in test end ); fun insert (eq:'a * 'a -> bool) (lst : 'a list) (what : 'a) = ( if present eq what lst then lst else (what :: lst) ); (* following cut down extract from a test script fails with: Exception- InternalError: Equality for function raised while compiling *) [ (insert (op =) []), (insert (op =) [1]) ];

Regards,

Rob.