Method throws

Method throws[12]:

RULE: ThrownType ::= TypeName COMPUTE
  IF(NOT(IsCoercible(FinalType(TypeName.Type),throwableType)),
    message(
     ERROR,
     CatStrInd("Must be throwable: ",TypeName.Sym),
     0,
     COORDREF))
    <- INCLUDING Goal.GotAllConstants;
END;

This macro is invoked in definition 11.