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Isomorphism

Relationship between sets defined by functions

R and S are isomorphic if there is a pair of functions

f: R => S

g: S => R

f o g is identity on R

g o f is identity on S

f and g are then called isomorphisms.

Examples

• R={1,4,7} is isomorphic to S={2,4,6}
• A ×B is isomorphic to B ×A
• N is isomorphic to Z