Metamath Proof Explorer


Theorem ltcvrntr

Description: Non-transitive condition for the covers relation. (Contributed by NM, 18-Jun-2012)

Ref Expression
Hypotheses ltltncvr.b 𝐵 = ( Base ‘ 𝐾 )
ltltncvr.s < = ( lt ‘ 𝐾 )
ltltncvr.c 𝐶 = ( ⋖ ‘ 𝐾 )
Assertion ltcvrntr ( ( 𝐾𝐴 ∧ ( 𝑋𝐵𝑌𝐵𝑍𝐵 ) ) → ( ( 𝑋 < 𝑌𝑌 𝐶 𝑍 ) → ¬ 𝑋 𝐶 𝑍 ) )

Proof

Step Hyp Ref Expression
1 ltltncvr.b 𝐵 = ( Base ‘ 𝐾 )
2 ltltncvr.s < = ( lt ‘ 𝐾 )
3 ltltncvr.c 𝐶 = ( ⋖ ‘ 𝐾 )
4 1 2 3 cvrlt ( ( ( 𝐾𝐴𝑌𝐵𝑍𝐵 ) ∧ 𝑌 𝐶 𝑍 ) → 𝑌 < 𝑍 )
5 4 ex ( ( 𝐾𝐴𝑌𝐵𝑍𝐵 ) → ( 𝑌 𝐶 𝑍𝑌 < 𝑍 ) )
6 5 3adant3r1 ( ( 𝐾𝐴 ∧ ( 𝑋𝐵𝑌𝐵𝑍𝐵 ) ) → ( 𝑌 𝐶 𝑍𝑌 < 𝑍 ) )
7 1 2 3 ltltncvr ( ( 𝐾𝐴 ∧ ( 𝑋𝐵𝑌𝐵𝑍𝐵 ) ) → ( ( 𝑋 < 𝑌𝑌 < 𝑍 ) → ¬ 𝑋 𝐶 𝑍 ) )
8 6 7 sylan2d ( ( 𝐾𝐴 ∧ ( 𝑋𝐵𝑌𝐵𝑍𝐵 ) ) → ( ( 𝑋 < 𝑌𝑌 𝐶 𝑍 ) → ¬ 𝑋 𝐶 𝑍 ) )