If the second procedure of a PERFORM THRU is not defined after the first one, the source code is semantically incorrect and the program doesn’t
behave as expected.
Noncompliant code example
PERFORM SECOND-P THRU FIRST-P.
...
FIRST-P.
...
SECOND-P.
...
Compliant solution
PERFORM FIRST-P THRU SECOND-P.
...
FIRST-P.
...
SECOND-P.
...
