| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cntzrec.b | ⊢ 𝐵  =  ( Base ‘ 𝑀 ) | 
						
							| 2 |  | cntzrec.z | ⊢ 𝑍  =  ( Cntz ‘ 𝑀 ) | 
						
							| 3 |  | ralcom | ⊢ ( ∀ 𝑥  ∈  𝑆 ∀ 𝑦  ∈  𝑇 ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  ↔  ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 ) ) | 
						
							| 4 |  | eqcom | ⊢ ( ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  ↔  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  =  ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 ) ) | 
						
							| 5 | 4 | 2ralbii | ⊢ ( ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  ↔  ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  =  ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 ) ) | 
						
							| 6 | 3 5 | bitri | ⊢ ( ∀ 𝑥  ∈  𝑆 ∀ 𝑦  ∈  𝑇 ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  ↔  ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  =  ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 ) ) | 
						
							| 7 | 6 | a1i | ⊢ ( ( 𝑆  ⊆  𝐵  ∧  𝑇  ⊆  𝐵 )  →  ( ∀ 𝑥  ∈  𝑆 ∀ 𝑦  ∈  𝑇 ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  ↔  ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  =  ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 ) ) ) | 
						
							| 8 |  | eqid | ⊢ ( +g ‘ 𝑀 )  =  ( +g ‘ 𝑀 ) | 
						
							| 9 | 1 8 2 | sscntz | ⊢ ( ( 𝑆  ⊆  𝐵  ∧  𝑇  ⊆  𝐵 )  →  ( 𝑆  ⊆  ( 𝑍 ‘ 𝑇 )  ↔  ∀ 𝑥  ∈  𝑆 ∀ 𝑦  ∈  𝑇 ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 )  =  ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 ) ) ) | 
						
							| 10 | 1 8 2 | sscntz | ⊢ ( ( 𝑇  ⊆  𝐵  ∧  𝑆  ⊆  𝐵 )  →  ( 𝑇  ⊆  ( 𝑍 ‘ 𝑆 )  ↔  ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  =  ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 ) ) ) | 
						
							| 11 | 10 | ancoms | ⊢ ( ( 𝑆  ⊆  𝐵  ∧  𝑇  ⊆  𝐵 )  →  ( 𝑇  ⊆  ( 𝑍 ‘ 𝑆 )  ↔  ∀ 𝑦  ∈  𝑇 ∀ 𝑥  ∈  𝑆 ( 𝑦 ( +g ‘ 𝑀 ) 𝑥 )  =  ( 𝑥 ( +g ‘ 𝑀 ) 𝑦 ) ) ) | 
						
							| 12 | 7 9 11 | 3bitr4d | ⊢ ( ( 𝑆  ⊆  𝐵  ∧  𝑇  ⊆  𝐵 )  →  ( 𝑆  ⊆  ( 𝑍 ‘ 𝑇 )  ↔  𝑇  ⊆  ( 𝑍 ‘ 𝑆 ) ) ) |