|There's more than one way to do things|
Here is the Oracle procedure I'm trying to execute [...] create or replace PROCEDURE abc AS [...]
This is a PROCEDURE. In your first posting starting this thread, you tried to call it as a FUNCTION.
A FUNCTION is something else than a PROCEDURE. Functions must return values, procedures can not return anything. Assigning (or comparing) "the result" of a procedure is impossible, as there is no result, and there can't be one.
something:=someProcedure is invalid, Oracle told you that, and the Google results for "PLS-00222" would have told you that even more clearly. (And I told you that pretty clear, too.)
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)