| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opsrso.o | ⊢ 𝑂  =  ( ( 𝐼  ordPwSer  𝑅 ) ‘ 𝑇 ) | 
						
							| 2 |  | opsrso.i | ⊢ ( 𝜑  →  𝐼  ∈  𝑉 ) | 
						
							| 3 |  | opsrso.r | ⊢ ( 𝜑  →  𝑅  ∈  Toset ) | 
						
							| 4 |  | opsrso.t | ⊢ ( 𝜑  →  𝑇  ⊆  ( 𝐼  ×  𝐼 ) ) | 
						
							| 5 |  | opsrso.w | ⊢ ( 𝜑  →  𝑇  We  𝐼 ) | 
						
							| 6 |  | opsrso.l | ⊢  ≤   =  ( lt ‘ 𝑂 ) | 
						
							| 7 |  | opsrso.b | ⊢ 𝐵  =  ( Base ‘ 𝑂 ) | 
						
							| 8 | 1 2 3 4 5 | opsrtos | ⊢ ( 𝜑  →  𝑂  ∈  Toset ) | 
						
							| 9 |  | eqid | ⊢ ( le ‘ 𝑂 )  =  ( le ‘ 𝑂 ) | 
						
							| 10 | 7 9 6 | tosso | ⊢ ( 𝑂  ∈  Toset  →  ( 𝑂  ∈  Toset  ↔  (  ≤   Or  𝐵  ∧  (  I   ↾  𝐵 )  ⊆  ( le ‘ 𝑂 ) ) ) ) | 
						
							| 11 | 10 | ibi | ⊢ ( 𝑂  ∈  Toset  →  (  ≤   Or  𝐵  ∧  (  I   ↾  𝐵 )  ⊆  ( le ‘ 𝑂 ) ) ) | 
						
							| 12 | 8 11 | syl | ⊢ ( 𝜑  →  (  ≤   Or  𝐵  ∧  (  I   ↾  𝐵 )  ⊆  ( le ‘ 𝑂 ) ) ) | 
						
							| 13 | 12 | simpld | ⊢ ( 𝜑  →   ≤   Or  𝐵 ) |