| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elnmz.1 | ⊢ 𝑁  =  { 𝑥  ∈  𝑋  ∣  ∀ 𝑦  ∈  𝑋 ( ( 𝑥  +  𝑦 )  ∈  𝑆  ↔  ( 𝑦  +  𝑥 )  ∈  𝑆 ) } | 
						
							| 2 |  | nmzsubg.2 | ⊢ 𝑋  =  ( Base ‘ 𝐺 ) | 
						
							| 3 |  | nmzsubg.3 | ⊢  +   =  ( +g ‘ 𝐺 ) | 
						
							| 4 | 2 | subgss | ⊢ ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  →  𝑆  ⊆  𝑋 ) | 
						
							| 5 | 4 | sselda | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑧  ∈  𝑆 )  →  𝑧  ∈  𝑋 ) | 
						
							| 6 |  | simpll | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝑆  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 7 |  | subgrcl | ⊢ ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  →  𝐺  ∈  Grp ) | 
						
							| 8 | 6 7 | syl | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝐺  ∈  Grp ) | 
						
							| 9 | 6 4 | syl | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝑆  ⊆  𝑋 ) | 
						
							| 10 |  | simplrl | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝑧  ∈  𝑆 ) | 
						
							| 11 | 9 10 | sseldd | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝑧  ∈  𝑋 ) | 
						
							| 12 |  | eqid | ⊢ ( 0g ‘ 𝐺 )  =  ( 0g ‘ 𝐺 ) | 
						
							| 13 |  | eqid | ⊢ ( invg ‘ 𝐺 )  =  ( invg ‘ 𝐺 ) | 
						
							| 14 | 2 3 12 13 | grplinv | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑧  ∈  𝑋 )  →  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  𝑧 )  =  ( 0g ‘ 𝐺 ) ) | 
						
							| 15 | 8 11 14 | syl2anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  𝑧 )  =  ( 0g ‘ 𝐺 ) ) | 
						
							| 16 | 15 | oveq1d | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  𝑧 )  +  𝑤 )  =  ( ( 0g ‘ 𝐺 )  +  𝑤 ) ) | 
						
							| 17 | 13 | subginvcl | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑧  ∈  𝑆 )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  ∈  𝑆 ) | 
						
							| 18 | 6 10 17 | syl2anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  ∈  𝑆 ) | 
						
							| 19 | 9 18 | sseldd | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  ∈  𝑋 ) | 
						
							| 20 |  | simplrr | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝑤  ∈  𝑋 ) | 
						
							| 21 | 2 3 | grpass | ⊢ ( ( 𝐺  ∈  Grp  ∧  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  ∈  𝑋  ∧  𝑧  ∈  𝑋  ∧  𝑤  ∈  𝑋 ) )  →  ( ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  𝑧 )  +  𝑤 )  =  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  ( 𝑧  +  𝑤 ) ) ) | 
						
							| 22 | 8 19 11 20 21 | syl13anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  𝑧 )  +  𝑤 )  =  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  ( 𝑧  +  𝑤 ) ) ) | 
						
							| 23 | 2 3 12 | grplid | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑤  ∈  𝑋 )  →  ( ( 0g ‘ 𝐺 )  +  𝑤 )  =  𝑤 ) | 
						
							| 24 | 8 20 23 | syl2anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( 0g ‘ 𝐺 )  +  𝑤 )  =  𝑤 ) | 
						
							| 25 | 16 22 24 | 3eqtr3d | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  ( 𝑧  +  𝑤 ) )  =  𝑤 ) | 
						
							| 26 |  | simpr | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( 𝑧  +  𝑤 )  ∈  𝑆 ) | 
						
							| 27 | 3 | subgcl | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  ∈  𝑆  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  ( 𝑧  +  𝑤 ) )  ∈  𝑆 ) | 
						
							| 28 | 6 18 26 27 | syl3anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( ( ( invg ‘ 𝐺 ) ‘ 𝑧 )  +  ( 𝑧  +  𝑤 ) )  ∈  𝑆 ) | 
						
							| 29 | 25 28 | eqeltrrd | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  𝑤  ∈  𝑆 ) | 
						
							| 30 | 3 | subgcl | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑤  ∈  𝑆  ∧  𝑧  ∈  𝑆 )  →  ( 𝑤  +  𝑧 )  ∈  𝑆 ) | 
						
							| 31 | 6 29 10 30 | syl3anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑧  +  𝑤 )  ∈  𝑆 )  →  ( 𝑤  +  𝑧 )  ∈  𝑆 ) | 
						
							| 32 |  | simpll | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  𝑆  ∈  ( SubGrp ‘ 𝐺 ) ) | 
						
							| 33 |  | simplrl | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  𝑧  ∈  𝑆 ) | 
						
							| 34 | 32 7 | syl | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  𝐺  ∈  Grp ) | 
						
							| 35 |  | simplrr | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  𝑤  ∈  𝑋 ) | 
						
							| 36 | 32 33 5 | syl2anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  𝑧  ∈  𝑋 ) | 
						
							| 37 |  | eqid | ⊢ ( -g ‘ 𝐺 )  =  ( -g ‘ 𝐺 ) | 
						
							| 38 | 2 3 37 | grppncan | ⊢ ( ( 𝐺  ∈  Grp  ∧  𝑤  ∈  𝑋  ∧  𝑧  ∈  𝑋 )  →  ( ( 𝑤  +  𝑧 ) ( -g ‘ 𝐺 ) 𝑧 )  =  𝑤 ) | 
						
							| 39 | 34 35 36 38 | syl3anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  ( ( 𝑤  +  𝑧 ) ( -g ‘ 𝐺 ) 𝑧 )  =  𝑤 ) | 
						
							| 40 |  | simpr | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  ( 𝑤  +  𝑧 )  ∈  𝑆 ) | 
						
							| 41 | 37 | subgsubcl | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆  ∧  𝑧  ∈  𝑆 )  →  ( ( 𝑤  +  𝑧 ) ( -g ‘ 𝐺 ) 𝑧 )  ∈  𝑆 ) | 
						
							| 42 | 32 40 33 41 | syl3anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  ( ( 𝑤  +  𝑧 ) ( -g ‘ 𝐺 ) 𝑧 )  ∈  𝑆 ) | 
						
							| 43 | 39 42 | eqeltrrd | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  𝑤  ∈  𝑆 ) | 
						
							| 44 | 3 | subgcl | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑆 )  →  ( 𝑧  +  𝑤 )  ∈  𝑆 ) | 
						
							| 45 | 32 33 43 44 | syl3anc | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  ∧  ( 𝑤  +  𝑧 )  ∈  𝑆 )  →  ( 𝑧  +  𝑤 )  ∈  𝑆 ) | 
						
							| 46 | 31 45 | impbida | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  ( 𝑧  ∈  𝑆  ∧  𝑤  ∈  𝑋 ) )  →  ( ( 𝑧  +  𝑤 )  ∈  𝑆  ↔  ( 𝑤  +  𝑧 )  ∈  𝑆 ) ) | 
						
							| 47 | 46 | anassrs | ⊢ ( ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑧  ∈  𝑆 )  ∧  𝑤  ∈  𝑋 )  →  ( ( 𝑧  +  𝑤 )  ∈  𝑆  ↔  ( 𝑤  +  𝑧 )  ∈  𝑆 ) ) | 
						
							| 48 | 47 | ralrimiva | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑧  ∈  𝑆 )  →  ∀ 𝑤  ∈  𝑋 ( ( 𝑧  +  𝑤 )  ∈  𝑆  ↔  ( 𝑤  +  𝑧 )  ∈  𝑆 ) ) | 
						
							| 49 | 1 | elnmz | ⊢ ( 𝑧  ∈  𝑁  ↔  ( 𝑧  ∈  𝑋  ∧  ∀ 𝑤  ∈  𝑋 ( ( 𝑧  +  𝑤 )  ∈  𝑆  ↔  ( 𝑤  +  𝑧 )  ∈  𝑆 ) ) ) | 
						
							| 50 | 5 48 49 | sylanbrc | ⊢ ( ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  ∧  𝑧  ∈  𝑆 )  →  𝑧  ∈  𝑁 ) | 
						
							| 51 | 50 | ex | ⊢ ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  →  ( 𝑧  ∈  𝑆  →  𝑧  ∈  𝑁 ) ) | 
						
							| 52 | 51 | ssrdv | ⊢ ( 𝑆  ∈  ( SubGrp ‘ 𝐺 )  →  𝑆  ⊆  𝑁 ) |