| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							frmdmnd.m | 
							⊢ 𝑀  =  ( freeMnd ‘ 𝐼 )  | 
						
						
							| 2 | 
							
								
							 | 
							frmdgsum.u | 
							⊢ 𝑈  =  ( varFMnd ‘ 𝐼 )  | 
						
						
							| 3 | 
							
								
							 | 
							simpl1 | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝐼  ∈  𝑉 )  | 
						
						
							| 4 | 
							
								
							 | 
							simpl2 | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝐽  ⊆  𝐼 )  | 
						
						
							| 5 | 
							
								
							 | 
							sswrd | 
							⊢ ( 𝐽  ⊆  𝐼  →  Word  𝐽  ⊆  Word  𝐼 )  | 
						
						
							| 6 | 
							
								4 5
							 | 
							syl | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  Word  𝐽  ⊆  Word  𝐼 )  | 
						
						
							| 7 | 
							
								
							 | 
							simprr | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝑥  ∈  Word  𝐽 )  | 
						
						
							| 8 | 
							
								6 7
							 | 
							sseldd | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝑥  ∈  Word  𝐼 )  | 
						
						
							| 9 | 
							
								1 2
							 | 
							frmdgsum | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝑥  ∈  Word  𝐼 )  →  ( 𝑀  Σg  ( 𝑈  ∘  𝑥 ) )  =  𝑥 )  | 
						
						
							| 10 | 
							
								3 8 9
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( 𝑀  Σg  ( 𝑈  ∘  𝑥 ) )  =  𝑥 )  | 
						
						
							| 11 | 
							
								
							 | 
							simpl3 | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  | 
						
						
							| 12 | 
							
								
							 | 
							wrdf | 
							⊢ ( 𝑥  ∈  Word  𝐽  →  𝑥 : ( 0 ..^ ( ♯ ‘ 𝑥 ) ) ⟶ 𝐽 )  | 
						
						
							| 13 | 
							
								12
							 | 
							ad2antll | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝑥 : ( 0 ..^ ( ♯ ‘ 𝑥 ) ) ⟶ 𝐽 )  | 
						
						
							| 14 | 
							
								13
							 | 
							frnd | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ran  𝑥  ⊆  𝐽 )  | 
						
						
							| 15 | 
							
								
							 | 
							cores | 
							⊢ ( ran  𝑥  ⊆  𝐽  →  ( ( 𝑈  ↾  𝐽 )  ∘  𝑥 )  =  ( 𝑈  ∘  𝑥 ) )  | 
						
						
							| 16 | 
							
								14 15
							 | 
							syl | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( ( 𝑈  ↾  𝐽 )  ∘  𝑥 )  =  ( 𝑈  ∘  𝑥 ) )  | 
						
						
							| 17 | 
							
								2
							 | 
							vrmdf | 
							⊢ ( 𝐼  ∈  𝑉  →  𝑈 : 𝐼 ⟶ Word  𝐼 )  | 
						
						
							| 18 | 
							
								17
							 | 
							3ad2ant1 | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  𝑈 : 𝐼 ⟶ Word  𝐼 )  | 
						
						
							| 19 | 
							
								18
							 | 
							ffnd | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  𝑈  Fn  𝐼 )  | 
						
						
							| 20 | 
							
								
							 | 
							fnssres | 
							⊢ ( ( 𝑈  Fn  𝐼  ∧  𝐽  ⊆  𝐼 )  →  ( 𝑈  ↾  𝐽 )  Fn  𝐽 )  | 
						
						
							| 21 | 
							
								19 4 20
							 | 
							syl2an2r | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( 𝑈  ↾  𝐽 )  Fn  𝐽 )  | 
						
						
							| 22 | 
							
								
							 | 
							df-ima | 
							⊢ ( 𝑈  “  𝐽 )  =  ran  ( 𝑈  ↾  𝐽 )  | 
						
						
							| 23 | 
							
								
							 | 
							simprl | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( 𝑈  “  𝐽 )  ⊆  𝐴 )  | 
						
						
							| 24 | 
							
								22 23
							 | 
							eqsstrrid | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ran  ( 𝑈  ↾  𝐽 )  ⊆  𝐴 )  | 
						
						
							| 25 | 
							
								
							 | 
							df-f | 
							⊢ ( ( 𝑈  ↾  𝐽 ) : 𝐽 ⟶ 𝐴  ↔  ( ( 𝑈  ↾  𝐽 )  Fn  𝐽  ∧  ran  ( 𝑈  ↾  𝐽 )  ⊆  𝐴 ) )  | 
						
						
							| 26 | 
							
								21 24 25
							 | 
							sylanbrc | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( 𝑈  ↾  𝐽 ) : 𝐽 ⟶ 𝐴 )  | 
						
						
							| 27 | 
							
								
							 | 
							wrdco | 
							⊢ ( ( 𝑥  ∈  Word  𝐽  ∧  ( 𝑈  ↾  𝐽 ) : 𝐽 ⟶ 𝐴 )  →  ( ( 𝑈  ↾  𝐽 )  ∘  𝑥 )  ∈  Word  𝐴 )  | 
						
						
							| 28 | 
							
								7 26 27
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( ( 𝑈  ↾  𝐽 )  ∘  𝑥 )  ∈  Word  𝐴 )  | 
						
						
							| 29 | 
							
								16 28
							 | 
							eqeltrrd | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( 𝑈  ∘  𝑥 )  ∈  Word  𝐴 )  | 
						
						
							| 30 | 
							
								
							 | 
							gsumwsubmcl | 
							⊢ ( ( 𝐴  ∈  ( SubMnd ‘ 𝑀 )  ∧  ( 𝑈  ∘  𝑥 )  ∈  Word  𝐴 )  →  ( 𝑀  Σg  ( 𝑈  ∘  𝑥 ) )  ∈  𝐴 )  | 
						
						
							| 31 | 
							
								11 29 30
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  ( 𝑀  Σg  ( 𝑈  ∘  𝑥 ) )  ∈  𝐴 )  | 
						
						
							| 32 | 
							
								10 31
							 | 
							eqeltrrd | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ∧  𝑥  ∈  Word  𝐽 ) )  →  𝑥  ∈  𝐴 )  | 
						
						
							| 33 | 
							
								32
							 | 
							expr | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( 𝑈  “  𝐽 )  ⊆  𝐴 )  →  ( 𝑥  ∈  Word  𝐽  →  𝑥  ∈  𝐴 ) )  | 
						
						
							| 34 | 
							
								33
							 | 
							ssrdv | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  ( 𝑈  “  𝐽 )  ⊆  𝐴 )  →  Word  𝐽  ⊆  𝐴 )  | 
						
						
							| 35 | 
							
								34
							 | 
							ex | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  →  Word  𝐽  ⊆  𝐴 ) )  | 
						
						
							| 36 | 
							
								
							 | 
							simpl1 | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  𝑥  ∈  𝐽 )  →  𝐼  ∈  𝑉 )  | 
						
						
							| 37 | 
							
								
							 | 
							simp2 | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  𝐽  ⊆  𝐼 )  | 
						
						
							| 38 | 
							
								37
							 | 
							sselda | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  𝑥  ∈  𝐽 )  →  𝑥  ∈  𝐼 )  | 
						
						
							| 39 | 
							
								2
							 | 
							vrmdval | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝑥  ∈  𝐼 )  →  ( 𝑈 ‘ 𝑥 )  =  〈“ 𝑥 ”〉 )  | 
						
						
							| 40 | 
							
								36 38 39
							 | 
							syl2anc | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  𝑥  ∈  𝐽 )  →  ( 𝑈 ‘ 𝑥 )  =  〈“ 𝑥 ”〉 )  | 
						
						
							| 41 | 
							
								
							 | 
							simpr | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  𝑥  ∈  𝐽 )  →  𝑥  ∈  𝐽 )  | 
						
						
							| 42 | 
							
								41
							 | 
							s1cld | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  𝑥  ∈  𝐽 )  →  〈“ 𝑥 ”〉  ∈  Word  𝐽 )  | 
						
						
							| 43 | 
							
								40 42
							 | 
							eqeltrd | 
							⊢ ( ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  ∧  𝑥  ∈  𝐽 )  →  ( 𝑈 ‘ 𝑥 )  ∈  Word  𝐽 )  | 
						
						
							| 44 | 
							
								43
							 | 
							ralrimiva | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  ∀ 𝑥  ∈  𝐽 ( 𝑈 ‘ 𝑥 )  ∈  Word  𝐽 )  | 
						
						
							| 45 | 
							
								18
							 | 
							ffund | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  Fun  𝑈 )  | 
						
						
							| 46 | 
							
								18
							 | 
							fdmd | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  dom  𝑈  =  𝐼 )  | 
						
						
							| 47 | 
							
								37 46
							 | 
							sseqtrrd | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  𝐽  ⊆  dom  𝑈 )  | 
						
						
							| 48 | 
							
								
							 | 
							funimass4 | 
							⊢ ( ( Fun  𝑈  ∧  𝐽  ⊆  dom  𝑈 )  →  ( ( 𝑈  “  𝐽 )  ⊆  Word  𝐽  ↔  ∀ 𝑥  ∈  𝐽 ( 𝑈 ‘ 𝑥 )  ∈  Word  𝐽 ) )  | 
						
						
							| 49 | 
							
								45 47 48
							 | 
							syl2anc | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  ( ( 𝑈  “  𝐽 )  ⊆  Word  𝐽  ↔  ∀ 𝑥  ∈  𝐽 ( 𝑈 ‘ 𝑥 )  ∈  Word  𝐽 ) )  | 
						
						
							| 50 | 
							
								44 49
							 | 
							mpbird | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  ( 𝑈  “  𝐽 )  ⊆  Word  𝐽 )  | 
						
						
							| 51 | 
							
								
							 | 
							sstr2 | 
							⊢ ( ( 𝑈  “  𝐽 )  ⊆  Word  𝐽  →  ( Word  𝐽  ⊆  𝐴  →  ( 𝑈  “  𝐽 )  ⊆  𝐴 ) )  | 
						
						
							| 52 | 
							
								50 51
							 | 
							syl | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  ( Word  𝐽  ⊆  𝐴  →  ( 𝑈  “  𝐽 )  ⊆  𝐴 ) )  | 
						
						
							| 53 | 
							
								35 52
							 | 
							impbid | 
							⊢ ( ( 𝐼  ∈  𝑉  ∧  𝐽  ⊆  𝐼  ∧  𝐴  ∈  ( SubMnd ‘ 𝑀 ) )  →  ( ( 𝑈  “  𝐽 )  ⊆  𝐴  ↔  Word  𝐽  ⊆  𝐴 ) )  |