Inside a for loop, crystal angle 'd' defaults get changed by previous iteration

Accordingly, something like 
for(2,4){
    nonlinear(4,i29,i30,d,d)
    nonlinear(4,v01,v02, d, d)
}

will have different results than

for(2,4){
    nonlinear(4,d,d,d,d)
    nonlinear(4,v01,v02, d, d)
}