Metamath Proof Explorer


Theorem frege127

Description: Communte antecedents of frege126 . Proposition 127 of Frege1879 p. 82. (Contributed by RP, 9-Jul-2020) (Proof modification is discouraged.)

Ref Expression
Hypotheses frege123.x 𝑋𝑈
frege123.y 𝑌𝑉
frege124.m 𝑀𝑊
frege124.r 𝑅𝑆
Assertion frege127 ( Fun 𝑅 → ( 𝑌 ( t+ ‘ 𝑅 ) 𝑀 → ( 𝑌 𝑅 𝑋 → ( ¬ 𝑋 ( t+ ‘ 𝑅 ) 𝑀𝑀 ( ( t+ ‘ 𝑅 ) ∪ I ) 𝑋 ) ) ) )

Proof

Step Hyp Ref Expression
1 frege123.x 𝑋𝑈
2 frege123.y 𝑌𝑉
3 frege124.m 𝑀𝑊
4 frege124.r 𝑅𝑆
5 1 2 3 4 frege126 ( Fun 𝑅 → ( 𝑌 𝑅 𝑋 → ( 𝑌 ( t+ ‘ 𝑅 ) 𝑀 → ( ¬ 𝑋 ( t+ ‘ 𝑅 ) 𝑀𝑀 ( ( t+ ‘ 𝑅 ) ∪ I ) 𝑋 ) ) ) )
6 frege12 ( ( Fun 𝑅 → ( 𝑌 𝑅 𝑋 → ( 𝑌 ( t+ ‘ 𝑅 ) 𝑀 → ( ¬ 𝑋 ( t+ ‘ 𝑅 ) 𝑀𝑀 ( ( t+ ‘ 𝑅 ) ∪ I ) 𝑋 ) ) ) ) → ( Fun 𝑅 → ( 𝑌 ( t+ ‘ 𝑅 ) 𝑀 → ( 𝑌 𝑅 𝑋 → ( ¬ 𝑋 ( t+ ‘ 𝑅 ) 𝑀𝑀 ( ( t+ ‘ 𝑅 ) ∪ I ) 𝑋 ) ) ) ) )
7 5 6 ax-mp ( Fun 𝑅 → ( 𝑌 ( t+ ‘ 𝑅 ) 𝑀 → ( 𝑌 𝑅 𝑋 → ( ¬ 𝑋 ( t+ ‘ 𝑅 ) 𝑀𝑀 ( ( t+ ‘ 𝑅 ) ∪ I ) 𝑋 ) ) ) )