set A to 1
set B to 2
set C to 3
if(A = 1) if(B = 2) if(C = 3) message("Three times a lady!")
There are internal differences in the way if() statements are handled under RISC OS and Windows, though the end result is the same.
The RISC OS implementation does not poll between processing, though it is not anticipated that this would make much difference.
The Windows version is internally recursive, however it has been tested and proven with a line of code consisting of 1024 chained if() statements (the "IfInsane" test script)... this test script will not work under RISC OS as the maximum line length is 256 characters.