Database
CLASSICAL FIRST-ORDER LOGIC WITH EQUALITY
Propositional calculus
Logical conjunction
impd
Next ⟩
impcomd
Metamath Proof Explorer
Ascii
Unicode
Theorem
impd
Description:
Importation deduction.
(Contributed by
NM
, 31-Mar-1994)
Ref
Expression
Hypothesis
impd.1
⊢
φ
→
ψ
→
χ
→
θ
Assertion
impd
⊢
φ
→
ψ
∧
χ
→
θ
Proof
Step
Hyp
Ref
Expression
1
impd.1
⊢
φ
→
ψ
→
χ
→
θ
2
1
com3l
⊢
ψ
→
χ
→
φ
→
θ
3
2
imp
⊢
ψ
∧
χ
→
φ
→
θ
4
3
com12
⊢
φ
→
ψ
∧
χ
→
θ