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CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical conjunction
sylbida
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sylan2
Metamath Proof Explorer
Ascii
Unicode
Theorem
sylbida
Description:
A syllogism deduction.
(Contributed by
SN
, 16-Jul-2024)
Ref
Expression
Hypotheses
sylbida.1
⊢
φ
→
ψ
↔
χ
sylbida.2
⊢
φ
∧
χ
→
θ
Assertion
sylbida
⊢
φ
∧
ψ
→
θ
Proof
Step
Hyp
Ref
Expression
1
sylbida.1
⊢
φ
→
ψ
↔
χ
2
sylbida.2
⊢
φ
∧
χ
→
θ
3
1
biimpa
⊢
φ
∧
ψ
→
χ
4
3
2
syldan
⊢
φ
∧
ψ
→
θ