A function f is idempotent if: f(f(x)) = f(x) The "absolute value" function is idempotent: abs(abs(-42)) = abs(-42) The "squared" function is not: sq(sq(7)) != sq(7)
A function f is idempotent if: f(f(x)) = f(x) The "absolute value" function is idempotent: abs(abs(-42)) = abs(-42) The "squared" function is not: sq(sq(7)) != sq(7)