There are four so far... anyone want to see them

for (i=0; i+n; i--)
for (i=0; i<n; n--)
for (i=0;-i<n; i--)
for (i=0;~i<n; i--)

Neat question, not a very good introduction. Once someone finds three, they think they are a genius. Did someone find another?
By the way, the unary NOT is replacing a space (" ") just like the negative symbol