[fpc-pascal] Incompatible procedure types

[Hairy Pixels]

What does this error mean? It's comparing a pointer to a procedure to a procedure variable (a callback). The signature appears exactly the same "function(TSymbol;TSymbol):LongInt is nested" so what's the problem?

error: Incompatible type for arg no. 2: Got "<address of function(TSymbol;TSymbol):LongInt is nested;StdCall>", expected "TSList$1$crcCC4DE170_crc9A33B934.<procedure variable type of function(TSymbol;TSymbol):LongInt is nested;StdCall>"

Regards,
	Ryan Joseph