Step function?



Richard Fateman escribi?:
> if() is not a step function. Try unit_step.
>

That doesn't work either. Totalfourier just gives me back the integral 
of unit_step.
Integrals of unit_step that cross 0 don't work either (ie: 
integrate(unit_step(x),x,0,6) works, integrate(unit_step(x),x,-2,0) 
works, but integrate(unit_step(x),x,-4,6) doesn't work)



Ismael.