Will 'cut off' any value the stack's holding to the ceil's number.
in this syntax: A B CEIL
A will be cut off to B, providing that A>B
The following commands are not supported in versions earlier 2.46:
200 400 add 500 ceil .shoot store
stores 500 in .shoot .
100 100 add 500 ceil .shoot store
stores 200 in .shoot . Because the ceil isn't reached, no values are 'cut off.