| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isprs.b | ⊢ 𝐵  =  ( Base ‘ 𝐾 ) | 
						
							| 2 |  | isprs.l | ⊢  ≤   =  ( le ‘ 𝐾 ) | 
						
							| 3 | 1 2 | isprs | ⊢ ( 𝐾  ∈   Proset   ↔  ( 𝐾  ∈  V  ∧  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ∀ 𝑧  ∈  𝐵 ( 𝑥  ≤  𝑥  ∧  ( ( 𝑥  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑥  ≤  𝑧 ) ) ) ) | 
						
							| 4 | 3 | simprbi | ⊢ ( 𝐾  ∈   Proset   →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ∀ 𝑧  ∈  𝐵 ( 𝑥  ≤  𝑥  ∧  ( ( 𝑥  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑥  ≤  𝑧 ) ) ) | 
						
							| 5 |  | breq12 | ⊢ ( ( 𝑥  =  𝑋  ∧  𝑥  =  𝑋 )  →  ( 𝑥  ≤  𝑥  ↔  𝑋  ≤  𝑋 ) ) | 
						
							| 6 | 5 | anidms | ⊢ ( 𝑥  =  𝑋  →  ( 𝑥  ≤  𝑥  ↔  𝑋  ≤  𝑋 ) ) | 
						
							| 7 |  | breq1 | ⊢ ( 𝑥  =  𝑋  →  ( 𝑥  ≤  𝑦  ↔  𝑋  ≤  𝑦 ) ) | 
						
							| 8 | 7 | anbi1d | ⊢ ( 𝑥  =  𝑋  →  ( ( 𝑥  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  ↔  ( 𝑋  ≤  𝑦  ∧  𝑦  ≤  𝑧 ) ) ) | 
						
							| 9 |  | breq1 | ⊢ ( 𝑥  =  𝑋  →  ( 𝑥  ≤  𝑧  ↔  𝑋  ≤  𝑧 ) ) | 
						
							| 10 | 8 9 | imbi12d | ⊢ ( 𝑥  =  𝑋  →  ( ( ( 𝑥  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑥  ≤  𝑧 )  ↔  ( ( 𝑋  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑋  ≤  𝑧 ) ) ) | 
						
							| 11 | 6 10 | anbi12d | ⊢ ( 𝑥  =  𝑋  →  ( ( 𝑥  ≤  𝑥  ∧  ( ( 𝑥  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑥  ≤  𝑧 ) )  ↔  ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑋  ≤  𝑧 ) ) ) ) | 
						
							| 12 |  | breq2 | ⊢ ( 𝑦  =  𝑌  →  ( 𝑋  ≤  𝑦  ↔  𝑋  ≤  𝑌 ) ) | 
						
							| 13 |  | breq1 | ⊢ ( 𝑦  =  𝑌  →  ( 𝑦  ≤  𝑧  ↔  𝑌  ≤  𝑧 ) ) | 
						
							| 14 | 12 13 | anbi12d | ⊢ ( 𝑦  =  𝑌  →  ( ( 𝑋  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  ↔  ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑧 ) ) ) | 
						
							| 15 | 14 | imbi1d | ⊢ ( 𝑦  =  𝑌  →  ( ( ( 𝑋  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑋  ≤  𝑧 )  ↔  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑧 )  →  𝑋  ≤  𝑧 ) ) ) | 
						
							| 16 | 15 | anbi2d | ⊢ ( 𝑦  =  𝑌  →  ( ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑋  ≤  𝑧 ) )  ↔  ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑧 )  →  𝑋  ≤  𝑧 ) ) ) ) | 
						
							| 17 |  | breq2 | ⊢ ( 𝑧  =  𝑍  →  ( 𝑌  ≤  𝑧  ↔  𝑌  ≤  𝑍 ) ) | 
						
							| 18 | 17 | anbi2d | ⊢ ( 𝑧  =  𝑍  →  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑧 )  ↔  ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑍 ) ) ) | 
						
							| 19 |  | breq2 | ⊢ ( 𝑧  =  𝑍  →  ( 𝑋  ≤  𝑧  ↔  𝑋  ≤  𝑍 ) ) | 
						
							| 20 | 18 19 | imbi12d | ⊢ ( 𝑧  =  𝑍  →  ( ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑧 )  →  𝑋  ≤  𝑧 )  ↔  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑍 )  →  𝑋  ≤  𝑍 ) ) ) | 
						
							| 21 | 20 | anbi2d | ⊢ ( 𝑧  =  𝑍  →  ( ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑧 )  →  𝑋  ≤  𝑧 ) )  ↔  ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑍 )  →  𝑋  ≤  𝑍 ) ) ) ) | 
						
							| 22 | 11 16 21 | rspc3v | ⊢ ( ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 )  →  ( ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐵 ∀ 𝑧  ∈  𝐵 ( 𝑥  ≤  𝑥  ∧  ( ( 𝑥  ≤  𝑦  ∧  𝑦  ≤  𝑧 )  →  𝑥  ≤  𝑧 ) )  →  ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑍 )  →  𝑋  ≤  𝑍 ) ) ) ) | 
						
							| 23 | 4 22 | mpan9 | ⊢ ( ( 𝐾  ∈   Proset   ∧  ( 𝑋  ∈  𝐵  ∧  𝑌  ∈  𝐵  ∧  𝑍  ∈  𝐵 ) )  →  ( 𝑋  ≤  𝑋  ∧  ( ( 𝑋  ≤  𝑌  ∧  𝑌  ≤  𝑍 )  →  𝑋  ≤  𝑍 ) ) ) |