Theorem hadifp 1606

Description: The value of the adder sum is, if the first input is true, the biconditionality, and if the first input is false, the exclusive disjunction, of the other two inputs. (Contributed by BJ, 11-Aug-2020.)

Assertion

Ref	Expression
hadifp	⊢ (hadd(𝜑, 𝜓, 𝜒) ↔ if-(𝜑, (𝜓 ↔ 𝜒), (𝜓 ⊻ 𝜒)))

Proof of Theorem hadifp

Step	Hyp	Ref	Expression
1		had1 1604	. 2 ⊢ (𝜑 → (hadd(𝜑, 𝜓, 𝜒) ↔ (𝜓 ↔ 𝜒)))
2		had0 1605	. 2 ⊢ (¬ 𝜑 → (hadd(𝜑, 𝜓, 𝜒) ↔ (𝜓 ⊻ 𝜒)))
3	1, 2	casesifp 1077	1 ⊢ (hadd(𝜑, 𝜓, 𝜒) ↔ if-(𝜑, (𝜓 ↔ 𝜒), (𝜓 ⊻ 𝜒)))

Syntax hints:   ↔ wb 205  if-wif 1061   ⊻ wxo 1509  haddwhad 1594

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 206  df-an 397  df-or 846  df-ifp 1062  df-xor 1510  df-had 1595

This theorem is referenced by:  wl-df-3xor  36137