When building a network it is natural to assign locations to an ARTIFICIAL CELLs using
RANGE x,y,z
be aware that this translates in the .c header to eg
#define x _p[32]
#define y _p[33]
#define z _p[34]
if you now use x, y or z in a VERBATIM block, there will be precompilation translation of those variables
this was surprisingly difficult to track down since the effects under the debugger appeared contradictory