| Step | Hyp | Ref | Expression | 
						
							| 1 |  | tngbas.t | ⊢ 𝑇  =  ( 𝐺  toNrmGrp  𝑁 ) | 
						
							| 2 |  | tngtset.2 | ⊢ 𝐷  =  ( dist ‘ 𝑇 ) | 
						
							| 3 |  | tngtset.3 | ⊢ 𝐽  =  ( MetOpen ‘ 𝐷 ) | 
						
							| 4 | 1 2 3 | tngtset | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  𝐽  =  ( TopSet ‘ 𝑇 ) ) | 
						
							| 5 |  | df-mopn | ⊢ MetOpen  =  ( 𝑥  ∈  ∪  ran  ∞Met  ↦  ( topGen ‘ ran  ( ball ‘ 𝑥 ) ) ) | 
						
							| 6 | 5 | dmmptss | ⊢ dom  MetOpen  ⊆  ∪  ran  ∞Met | 
						
							| 7 | 6 | sseli | ⊢ ( 𝐷  ∈  dom  MetOpen  →  𝐷  ∈  ∪  ran  ∞Met ) | 
						
							| 8 |  | eqid | ⊢ ( -g ‘ 𝐺 )  =  ( -g ‘ 𝐺 ) | 
						
							| 9 | 1 8 | tngds | ⊢ ( 𝑁  ∈  𝑊  →  ( 𝑁  ∘  ( -g ‘ 𝐺 ) )  =  ( dist ‘ 𝑇 ) ) | 
						
							| 10 | 9 2 | eqtr4di | ⊢ ( 𝑁  ∈  𝑊  →  ( 𝑁  ∘  ( -g ‘ 𝐺 ) )  =  𝐷 ) | 
						
							| 11 | 10 | adantl | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  ( 𝑁  ∘  ( -g ‘ 𝐺 ) )  =  𝐷 ) | 
						
							| 12 | 11 | dmeqd | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  dom  ( 𝑁  ∘  ( -g ‘ 𝐺 ) )  =  dom  𝐷 ) | 
						
							| 13 |  | dmcoss | ⊢ dom  ( 𝑁  ∘  ( -g ‘ 𝐺 ) )  ⊆  dom  ( -g ‘ 𝐺 ) | 
						
							| 14 |  | eqid | ⊢ ( Base ‘ 𝐺 )  =  ( Base ‘ 𝐺 ) | 
						
							| 15 |  | eqid | ⊢ ( +g ‘ 𝐺 )  =  ( +g ‘ 𝐺 ) | 
						
							| 16 |  | eqid | ⊢ ( invg ‘ 𝐺 )  =  ( invg ‘ 𝐺 ) | 
						
							| 17 | 14 15 16 8 | grpsubfval | ⊢ ( -g ‘ 𝐺 )  =  ( 𝑥  ∈  ( Base ‘ 𝐺 ) ,  𝑦  ∈  ( Base ‘ 𝐺 )  ↦  ( 𝑥 ( +g ‘ 𝐺 ) ( ( invg ‘ 𝐺 ) ‘ 𝑦 ) ) ) | 
						
							| 18 |  | ovex | ⊢ ( 𝑥 ( +g ‘ 𝐺 ) ( ( invg ‘ 𝐺 ) ‘ 𝑦 ) )  ∈  V | 
						
							| 19 | 17 18 | dmmpo | ⊢ dom  ( -g ‘ 𝐺 )  =  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) ) | 
						
							| 20 | 13 19 | sseqtri | ⊢ dom  ( 𝑁  ∘  ( -g ‘ 𝐺 ) )  ⊆  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) ) | 
						
							| 21 | 12 20 | eqsstrrdi | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  dom  𝐷  ⊆  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) ) ) | 
						
							| 22 | 21 | adantr | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  dom  𝐷  ⊆  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) ) ) | 
						
							| 23 |  | dmss | ⊢ ( dom  𝐷  ⊆  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) )  →  dom  dom  𝐷  ⊆  dom  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) ) ) | 
						
							| 24 | 22 23 | syl | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  dom  dom  𝐷  ⊆  dom  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) ) ) | 
						
							| 25 |  | dmxpid | ⊢ dom  ( ( Base ‘ 𝐺 )  ×  ( Base ‘ 𝐺 ) )  =  ( Base ‘ 𝐺 ) | 
						
							| 26 | 24 25 | sseqtrdi | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  dom  dom  𝐷  ⊆  ( Base ‘ 𝐺 ) ) | 
						
							| 27 |  | simpr | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  𝐷  ∈  ∪  ran  ∞Met ) | 
						
							| 28 |  | xmetunirn | ⊢ ( 𝐷  ∈  ∪  ran  ∞Met  ↔  𝐷  ∈  ( ∞Met ‘ dom  dom  𝐷 ) ) | 
						
							| 29 | 27 28 | sylib | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  𝐷  ∈  ( ∞Met ‘ dom  dom  𝐷 ) ) | 
						
							| 30 |  | eqid | ⊢ ( MetOpen ‘ 𝐷 )  =  ( MetOpen ‘ 𝐷 ) | 
						
							| 31 | 30 | mopnuni | ⊢ ( 𝐷  ∈  ( ∞Met ‘ dom  dom  𝐷 )  →  dom  dom  𝐷  =  ∪  ( MetOpen ‘ 𝐷 ) ) | 
						
							| 32 | 29 31 | syl | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  dom  dom  𝐷  =  ∪  ( MetOpen ‘ 𝐷 ) ) | 
						
							| 33 | 1 14 | tngbas | ⊢ ( 𝑁  ∈  𝑊  →  ( Base ‘ 𝐺 )  =  ( Base ‘ 𝑇 ) ) | 
						
							| 34 | 33 | ad2antlr | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  ( Base ‘ 𝐺 )  =  ( Base ‘ 𝑇 ) ) | 
						
							| 35 | 26 32 34 | 3sstr3d | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  ∪  ( MetOpen ‘ 𝐷 )  ⊆  ( Base ‘ 𝑇 ) ) | 
						
							| 36 |  | sspwuni | ⊢ ( ( MetOpen ‘ 𝐷 )  ⊆  𝒫  ( Base ‘ 𝑇 )  ↔  ∪  ( MetOpen ‘ 𝐷 )  ⊆  ( Base ‘ 𝑇 ) ) | 
						
							| 37 | 35 36 | sylibr | ⊢ ( ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  ∧  𝐷  ∈  ∪  ran  ∞Met )  →  ( MetOpen ‘ 𝐷 )  ⊆  𝒫  ( Base ‘ 𝑇 ) ) | 
						
							| 38 | 37 | ex | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  ( 𝐷  ∈  ∪  ran  ∞Met  →  ( MetOpen ‘ 𝐷 )  ⊆  𝒫  ( Base ‘ 𝑇 ) ) ) | 
						
							| 39 | 7 38 | syl5 | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  ( 𝐷  ∈  dom  MetOpen  →  ( MetOpen ‘ 𝐷 )  ⊆  𝒫  ( Base ‘ 𝑇 ) ) ) | 
						
							| 40 |  | ndmfv | ⊢ ( ¬  𝐷  ∈  dom  MetOpen  →  ( MetOpen ‘ 𝐷 )  =  ∅ ) | 
						
							| 41 |  | 0ss | ⊢ ∅  ⊆  𝒫  ( Base ‘ 𝑇 ) | 
						
							| 42 | 40 41 | eqsstrdi | ⊢ ( ¬  𝐷  ∈  dom  MetOpen  →  ( MetOpen ‘ 𝐷 )  ⊆  𝒫  ( Base ‘ 𝑇 ) ) | 
						
							| 43 | 39 42 | pm2.61d1 | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  ( MetOpen ‘ 𝐷 )  ⊆  𝒫  ( Base ‘ 𝑇 ) ) | 
						
							| 44 | 3 43 | eqsstrid | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  𝐽  ⊆  𝒫  ( Base ‘ 𝑇 ) ) | 
						
							| 45 | 4 44 | eqsstrrd | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  ( TopSet ‘ 𝑇 )  ⊆  𝒫  ( Base ‘ 𝑇 ) ) | 
						
							| 46 |  | eqid | ⊢ ( Base ‘ 𝑇 )  =  ( Base ‘ 𝑇 ) | 
						
							| 47 |  | eqid | ⊢ ( TopSet ‘ 𝑇 )  =  ( TopSet ‘ 𝑇 ) | 
						
							| 48 | 46 47 | topnid | ⊢ ( ( TopSet ‘ 𝑇 )  ⊆  𝒫  ( Base ‘ 𝑇 )  →  ( TopSet ‘ 𝑇 )  =  ( TopOpen ‘ 𝑇 ) ) | 
						
							| 49 | 45 48 | syl | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  ( TopSet ‘ 𝑇 )  =  ( TopOpen ‘ 𝑇 ) ) | 
						
							| 50 | 4 49 | eqtrd | ⊢ ( ( 𝐺  ∈  𝑉  ∧  𝑁  ∈  𝑊 )  →  𝐽  =  ( TopOpen ‘ 𝑇 ) ) |