I have the following functions.
for i from 1 to N do
phi[i](t):=piecewise(t>=x[i-1] and x[i]>t, (t-x[i])/(h), x[i]
## my goal is solve the integrals involving phi[i]'s as integrand and x[i]'s as its limits.
## as a test case I tried to calculate Int( diff( phi, t)* diff( phi, t), t=x..x);
V:=Int(diff(phi(t), t)*diff(phi(t), t), t=x..x);
addionally assuming(x<x and x<x
## The output pretty much looks what we get by hand, but there are plently
of Heaviside functions involve.
By a simple look at the output those Heaviside functions have to
disappear by using the order x>x>x.
But it isnt.
Would any body please point out my mistake or give me some better idea?