Database
SUPPLEMENTARY MATERIAL (USERS' MATHBOXES)
Mathbox for Jarvin Udandy
aifftbifffaibif
Metamath Proof Explorer
Description: Given a is equivalent to T., Given b is equivalent to F., there exists a
proof for that a implies b is false. (Contributed by Jarvin Udandy , 7-Sep-2020)
Ref
Expression
Hypotheses
aifftbifffaibif.1
⊢ ( 𝜑 ↔ ⊤ )
aifftbifffaibif.2
⊢ ( 𝜓 ↔ ⊥ )
Assertion
aifftbifffaibif
⊢ ( ( 𝜑 → 𝜓 ) ↔ ⊥ )
Proof
Step
Hyp
Ref
Expression
1
aifftbifffaibif.1
⊢ ( 𝜑 ↔ ⊤ )
2
aifftbifffaibif.2
⊢ ( 𝜓 ↔ ⊥ )
3
1
aistia
⊢ 𝜑
4
2
aisfina
⊢ ¬ 𝜓
5
3 4
pm3.2i
⊢ ( 𝜑 ∧ ¬ 𝜓 )
6
annim
⊢ ( ( 𝜑 ∧ ¬ 𝜓 ) ↔ ¬ ( 𝜑 → 𝜓 ) )
7
6
biimpi
⊢ ( ( 𝜑 ∧ ¬ 𝜓 ) → ¬ ( 𝜑 → 𝜓 ) )
8
5 7
ax-mp
⊢ ¬ ( 𝜑 → 𝜓 )
9
8
bifal
⊢ ( ( 𝜑 → 𝜓 ) ↔ ⊥ )