The verify(expr1, expr2, permute_elements(elems)) and verify(expr1, expr2, permute_elements(elems, ver)) calling sequences return true if, after the permutations of elems is substituted into expr2, the test for equality or the verification ver is true.

This function is useful for comparing objects which may contain session dependent permutations of arbitrary constants.

The verification permute_elements(elems) is always symmetric. The verification permute_elements(elems, ver) is symmetric if and only if the verification ver is symmetric.