topology: the branch of pure mathematics that deals only with the properties of a figure X that hold for every figure into which X can be transformed with a one-to-one correspondence that is continuous in both directions
pure mathematics: the branches of mathematics that study and develop the principles of mathematics for their own sake rather than for their immediate usefulness
ocean sunfish: among the largest bony fish; pelagic fish having an oval compressed body with high dorsal and anal fins and caudal fin reduced to a rudder-like lobe; worldwide in warm waters