| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cvrle.b | ⊢ 𝐵  =  ( Base ‘ 𝐾 ) | 
						
							| 2 |  | cvrle.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 3 |  | cvrle.c | ⊢ 𝐶  =  (  ⋖  ‘ 𝐾 ) | 
						
							| 4 |  | eqid | ⊢ ( lt ‘ 𝐾 )  =  ( lt ‘ 𝐾 ) | 
						
							| 5 | 1 4 3 | cvrnbtwn | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ¬  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ∧  𝑍 ( lt ‘ 𝐾 ) 𝑌 ) ) | 
						
							| 6 |  | iman | ⊢ ( ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  →  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) )  ↔  ¬  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ¬  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) ) | 
						
							| 7 |  | neanior | ⊢ ( ( 𝑋  ≠  𝑍  ∧  𝑍  ≠  𝑌 )  ↔  ¬  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) | 
						
							| 8 | 7 | anbi2i | ⊢ ( ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ( 𝑋  ≠  𝑍  ∧  𝑍  ≠  𝑌 ) )  ↔  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ¬  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) ) | 
						
							| 9 |  | an4 | ⊢ ( ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ( 𝑋  ≠  𝑍  ∧  𝑍  ≠  𝑌 ) )  ↔  ( ( 𝑋  ≤  𝑍  ∧  𝑋  ≠  𝑍 )  ∧  ( 𝑍  ≤  𝑌  ∧  𝑍  ≠  𝑌 ) ) ) | 
						
							| 10 | 8 9 | bitr3i | ⊢ ( ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ¬  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) )  ↔  ( ( 𝑋  ≤  𝑍  ∧  𝑋  ≠  𝑍 )  ∧  ( 𝑍  ≤  𝑌  ∧  𝑍  ≠  𝑌 ) ) ) | 
						
							| 11 | 2 4 | pltval | ⊢ ( ( 𝐾  ∈  Poset  ∧  𝑋  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  →  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ↔  ( 𝑋  ≤  𝑍  ∧  𝑋  ≠  𝑍 ) ) ) | 
						
							| 12 | 11 | 3adant3r2 | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ↔  ( 𝑋  ≤  𝑍  ∧  𝑋  ≠  𝑍 ) ) ) | 
						
							| 13 | 2 4 | pltval | ⊢ ( ( 𝐾  ∈  Poset  ∧  𝑍  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  →  ( 𝑍 ( lt ‘ 𝐾 ) 𝑌  ↔  ( 𝑍  ≤  𝑌  ∧  𝑍  ≠  𝑌 ) ) ) | 
						
							| 14 | 13 | 3com23 | ⊢ ( ( 𝐾  ∈  Poset  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  →  ( 𝑍 ( lt ‘ 𝐾 ) 𝑌  ↔  ( 𝑍  ≤  𝑌  ∧  𝑍  ≠  𝑌 ) ) ) | 
						
							| 15 | 14 | 3adant3r1 | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( 𝑍 ( lt ‘ 𝐾 ) 𝑌  ↔  ( 𝑍  ≤  𝑌  ∧  𝑍  ≠  𝑌 ) ) ) | 
						
							| 16 | 12 15 | anbi12d | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ∧  𝑍 ( lt ‘ 𝐾 ) 𝑌 )  ↔  ( ( 𝑋  ≤  𝑍  ∧  𝑋  ≠  𝑍 )  ∧  ( 𝑍  ≤  𝑌  ∧  𝑍  ≠  𝑌 ) ) ) ) | 
						
							| 17 | 10 16 | bitr4id | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ¬  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) )  ↔  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ∧  𝑍 ( lt ‘ 𝐾 ) 𝑌 ) ) ) | 
						
							| 18 | 17 | notbid | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( ¬  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ∧  ¬  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) )  ↔  ¬  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ∧  𝑍 ( lt ‘ 𝐾 ) 𝑌 ) ) ) | 
						
							| 19 | 6 18 | bitr2id | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( ¬  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ∧  𝑍 ( lt ‘ 𝐾 ) 𝑌 )  ↔  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  →  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) ) ) | 
						
							| 20 | 19 | 3adant3 | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( ¬  ( 𝑋 ( lt ‘ 𝐾 ) 𝑍  ∧  𝑍 ( lt ‘ 𝐾 ) 𝑌 )  ↔  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  →  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) ) ) | 
						
							| 21 | 5 20 | mpbid | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  →  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) ) | 
						
							| 22 | 1 2 | posref | ⊢ ( ( 𝐾  ∈  Poset  ∧  𝑍  ∈  𝐵 )  →  𝑍  ≤  𝑍 ) | 
						
							| 23 | 22 | 3ad2antr3 | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  𝑍  ≤  𝑍 ) | 
						
							| 24 | 23 | 3adant3 | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  𝑍  ≤  𝑍 ) | 
						
							| 25 |  | breq1 | ⊢ ( 𝑋  =  𝑍  →  ( 𝑋  ≤  𝑍  ↔  𝑍  ≤  𝑍 ) ) | 
						
							| 26 | 24 25 | syl5ibrcom | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( 𝑋  =  𝑍  →  𝑋  ≤  𝑍 ) ) | 
						
							| 27 | 1 2 3 | cvrle | ⊢ ( ( ( 𝐾  ∈  Poset  ∧  𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  𝑋  ≤  𝑌 ) | 
						
							| 28 | 27 | ex | ⊢ ( ( 𝐾  ∈  Poset  ∧  𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵 )  →  ( 𝑋 𝐶 𝑌  →  𝑋  ≤  𝑌 ) ) | 
						
							| 29 | 28 | 3adant3r3 | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( 𝑋 𝐶 𝑌  →  𝑋  ≤  𝑌 ) ) | 
						
							| 30 | 29 | 3impia | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  𝑋  ≤  𝑌 ) | 
						
							| 31 |  | breq2 | ⊢ ( 𝑍  =  𝑌  →  ( 𝑋  ≤  𝑍  ↔  𝑋  ≤  𝑌 ) ) | 
						
							| 32 | 30 31 | syl5ibrcom | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( 𝑍  =  𝑌  →  𝑋  ≤  𝑍 ) ) | 
						
							| 33 | 26 32 | jaod | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 )  →  𝑋  ≤  𝑍 ) ) | 
						
							| 34 |  | breq1 | ⊢ ( 𝑋  =  𝑍  →  ( 𝑋  ≤  𝑌  ↔  𝑍  ≤  𝑌 ) ) | 
						
							| 35 | 30 34 | syl5ibcom | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( 𝑋  =  𝑍  →  𝑍  ≤  𝑌 ) ) | 
						
							| 36 |  | breq2 | ⊢ ( 𝑍  =  𝑌  →  ( 𝑍  ≤  𝑍  ↔  𝑍  ≤  𝑌 ) ) | 
						
							| 37 | 24 36 | syl5ibcom | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( 𝑍  =  𝑌  →  𝑍  ≤  𝑌 ) ) | 
						
							| 38 | 35 37 | jaod | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 )  →  𝑍  ≤  𝑌 ) ) | 
						
							| 39 | 33 38 | jcad | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 )  →  ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 ) ) ) | 
						
							| 40 | 21 39 | impbid | ⊢ ( ( 𝐾  ∈  Poset  ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  ∧  𝑋 𝐶 𝑌 )  →  ( ( 𝑋  ≤  𝑍  ∧  𝑍  ≤  𝑌 )  ↔  ( 𝑋  =  𝑍  ∨  𝑍  =  𝑌 ) ) ) |