Wrong n. of rows in MAL plan?

Could you give me a feedback on whether this is a possible bug or not? In the following excerpt: X_377=[9]:bat[:str] := mat.packIncrement(X_376=[9]:bat[:str],X_335=[0]:bat[:str]);"] ... ... X_100=[10]:bat[:str] := mat.packIncrement(X_377=[10]:bat[:str],X_336=[1]:bat[:str]);"] X_377 has 9 rows. But when it's used as a parameter for X_100, it is reported to have 10 rows. In between the two instructions above, X_377 is never used. Roberto