C.4  Passing Data to and from External Predicates in C

These two functions are only meaningful inside C functions that have been called from ECLⁱPS^e as external predicates.

pword ec_arg(int i)

If inside a C function called from ECLⁱPS^e, this returns the i’th argument of the call.

int ec_unify(pword,pword)

Unify the two given pwords. Note that, if attributed variables are involved in the unification, the associated unification handlers as well as subsequent waking will only happen once control is returned to ECLⁱPS^e.