||Finds all pythagorean triangles (right triangles with integer sides)
||Note the use of a diagonalising ZF expression (`//' instead of `|')
||To see the triangles, say
||	output

output = lay (map show pyths)
pyths = [(a,b,intsqrt(a*a+b*b))//a<-[3..];b<-[a+1..];is_sq(a*a+b*b)]
intsqrt x = entier(sqrt x)
is_sq y = (intsqrt y)^ 2 = y
