CIGAL Reference Manual, Chapter 2 (Commands): NEXT
usage: next [nloop]
Use NEXT within a program loop that started with a WHILE or REPEAT command to return to the beginning of the loop. When using nested loops you move to the beginning of one of the outer loops by specifying the NLOOP argument. For example, a NLOOP of 1 means the innermost loop (this is the default), NLOOP of 2 means jump to the beginning of the second innermost loop, etc.
BREAK(2), REPEAT(2), WHILE(2)