Theorem hadifp 1602

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 1600	. 2 ⊢ (𝜑 → (hadd(𝜑, 𝜓, 𝜒) ↔ (𝜓 ↔ 𝜒)))
2		had0 1601	. 2 ⊢ (¬ 𝜑 → (hadd(𝜑, 𝜓, 𝜒) ↔ (𝜓 ⊻ 𝜒)))
3	1, 2	casesifp 1078	1 ⊢ (hadd(𝜑, 𝜓, 𝜒) ↔ if-(𝜑, (𝜓 ↔ 𝜒), (𝜓 ⊻ 𝜒)))

Syntax hints:   ↔ wb 206  if-wif 1063   ⊻ wxo 1508  haddwhad 1590

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 207  df-an 396  df-or 847  df-ifp 1064  df-xor 1509  df-had 1591

This theorem is referenced by:  wl-df-3xor  37434