is this meant to be
IF NZ G.BTNV: P.HERE - G.BTNI * 11 G.GRPI?
placing them on separate lines will not achieve this, so
P.HERE will be executed regardless of
G.BTNV state. a simpler way might be doing
IF EZ G.BTNV: BREAK instead.
IF treats any non zero results as true, so instead of
IF NZ G.BTNV you can simply do