Metamath Proof Explorer


Theorem twonotinotbothi

Description: From these two negated implications it is not the case their nonnegated forms are both true. (Contributed by Jarvin Udandy, 11-Sep-2020)

Ref Expression
Hypotheses twonotinotbothi.1 ¬ ( 𝜑𝜓 )
twonotinotbothi.2 ¬ ( 𝜒𝜃 )
Assertion twonotinotbothi ¬ ( ( 𝜑𝜓 ) ∧ ( 𝜒𝜃 ) )

Proof

Step Hyp Ref Expression
1 twonotinotbothi.1 ¬ ( 𝜑𝜓 )
2 twonotinotbothi.2 ¬ ( 𝜒𝜃 )
3 1 orci ( ¬ ( 𝜑𝜓 ) ∨ ¬ ( 𝜒𝜃 ) )
4 pm3.14 ( ( ¬ ( 𝜑𝜓 ) ∨ ¬ ( 𝜒𝜃 ) ) → ¬ ( ( 𝜑𝜓 ) ∧ ( 𝜒𝜃 ) ) )
5 3 4 ax-mp ¬ ( ( 𝜑𝜓 ) ∧ ( 𝜒𝜃 ) )