hi,

i just started learning about PDE in complex variables and im very confused by it.

why isit that for f(x) = integrate from 2pi to 0 ( H(x-t)) dt

that if t<x, H(x-t) = 1 and for t>x, H(x-t) = 0?

what does that mean?

also, is there any books on notes that anyone can recommend which explains this concept becos i cant seem to find any materials on this.

thanks