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SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Richard Penner
Short Studies
Additional work on conditional logical operator
ifpan23
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ifpdfor2
Metamath Proof Explorer
Ascii
Unicode
Theorem
ifpan23
Description:
Conjunction of conditional logical operators.
(Contributed by
RP
, 20-Apr-2020)
Ref
Expression
Assertion
ifpan23
⊢
if-
φ
ψ
χ
∧
if-
φ
θ
τ
↔
if-
φ
ψ
∧
θ
χ
∧
τ
Proof
Step
Hyp
Ref
Expression
1
ifpan123g
⊢
if-
φ
ψ
χ
∧
if-
φ
θ
τ
↔
¬
φ
∨
ψ
∧
φ
∨
χ
∧
¬
φ
∨
θ
∧
φ
∨
τ
2
an4
⊢
¬
φ
∨
ψ
∧
φ
∨
χ
∧
¬
φ
∨
θ
∧
φ
∨
τ
↔
¬
φ
∨
ψ
∧
¬
φ
∨
θ
∧
φ
∨
χ
∧
φ
∨
τ
3
dfifp4
⊢
if-
φ
ψ
∧
θ
χ
∧
τ
↔
¬
φ
∨
ψ
∧
θ
∧
φ
∨
χ
∧
τ
4
ordi
⊢
¬
φ
∨
ψ
∧
θ
↔
¬
φ
∨
ψ
∧
¬
φ
∨
θ
5
ordi
⊢
φ
∨
χ
∧
τ
↔
φ
∨
χ
∧
φ
∨
τ
6
4
5
anbi12i
⊢
¬
φ
∨
ψ
∧
θ
∧
φ
∨
χ
∧
τ
↔
¬
φ
∨
ψ
∧
¬
φ
∨
θ
∧
φ
∨
χ
∧
φ
∨
τ
7
3
6
bitr2i
⊢
¬
φ
∨
ψ
∧
¬
φ
∨
θ
∧
φ
∨
χ
∧
φ
∨
τ
↔
if-
φ
ψ
∧
θ
χ
∧
τ
8
1
2
7
3bitri
⊢
if-
φ
ψ
χ
∧
if-
φ
θ
τ
↔
if-
φ
ψ
∧
θ
χ
∧
τ