STEP
STEP(Arg) will return a value of 1 if the argument is greater than or equal to zero; otherwise the STEP function will return zero. The STEP function can be used to provide conditional assignments similar to the IF function. For example, the following equation will set A=B if Z>=5 and A=C if Z<5.
A = Step(Z - 5) * B + (1-Step(Z - 5)) * C