Argument 1 of function 'X' is declared as optional in the previous definition, but not in the current definition.
or Argument 3 of function 'X' has an initial value in an ELSEWHERE definition, but does not in the AS definition.
or The required definition for function 'X' has parentheses, but the supplied definition has none.
There is a mismatch between two function signatures that should be the
same: an ELSEWHERE and AS definition of the
function, SUPPLY and REQUIRE definition, or
function definition in interface module and the one in the
implementation module are not the same.