I had to double-take since in Python a common alternative to trick ? treat : notreat is (trick and treat) or notreat
But I don't think this translates to overlapping circles very well. "trick implies treat" is only defined inside the trick circle, outside is undefined if treat is true or not.
I'm not going to draw a diagram, but here's the "truth table" for A implies B:
A, B, A -> B
N, N, undefined
N, Y, undefined
Y, N, false
Y, Y, true