| Step | Hyp | Ref | Expression | 
						
							| 1 |  | clwlkclwwlkf.c | ⊢ 𝐶  =  { 𝑤  ∈  ( ClWalks ‘ 𝐺 )  ∣  1  ≤  ( ♯ ‘ ( 1st  ‘ 𝑤 ) ) } | 
						
							| 2 |  | clwlkclwwlkf.f | ⊢ 𝐹  =  ( 𝑐  ∈  𝐶  ↦  ( ( 2nd  ‘ 𝑐 )  prefix  ( ( ♯ ‘ ( 2nd  ‘ 𝑐 ) )  −  1 ) ) ) | 
						
							| 3 | 1 2 | clwlkclwwlkf | ⊢ ( 𝐺  ∈  USPGraph  →  𝐹 : 𝐶 ⟶ ( ClWWalks ‘ 𝐺 ) ) | 
						
							| 4 |  | clwwlkgt0 | ⊢ ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  0  <  ( ♯ ‘ 𝑤 ) ) | 
						
							| 5 |  | eqid | ⊢ ( Vtx ‘ 𝐺 )  =  ( Vtx ‘ 𝐺 ) | 
						
							| 6 | 5 | clwwlkbp | ⊢ ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  ( 𝐺  ∈  V  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  𝑤  ≠  ∅ ) ) | 
						
							| 7 |  | lencl | ⊢ ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  →  ( ♯ ‘ 𝑤 )  ∈  ℕ0 ) | 
						
							| 8 | 7 | nn0zd | ⊢ ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  →  ( ♯ ‘ 𝑤 )  ∈  ℤ ) | 
						
							| 9 |  | zgt0ge1 | ⊢ ( ( ♯ ‘ 𝑤 )  ∈  ℤ  →  ( 0  <  ( ♯ ‘ 𝑤 )  ↔  1  ≤  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 10 | 8 9 | syl | ⊢ ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  →  ( 0  <  ( ♯ ‘ 𝑤 )  ↔  1  ≤  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 11 | 10 | biimpd | ⊢ ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  →  ( 0  <  ( ♯ ‘ 𝑤 )  →  1  ≤  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 12 | 11 | anc2li | ⊢ ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  →  ( 0  <  ( ♯ ‘ 𝑤 )  →  ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) ) ) | 
						
							| 13 | 12 | 3ad2ant2 | ⊢ ( ( 𝐺  ∈  V  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  𝑤  ≠  ∅ )  →  ( 0  <  ( ♯ ‘ 𝑤 )  →  ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) ) ) | 
						
							| 14 | 6 13 | syl | ⊢ ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  ( 0  <  ( ♯ ‘ 𝑤 )  →  ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) ) ) | 
						
							| 15 | 4 14 | mpd | ⊢ ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 16 | 15 | adantl | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  ( ClWWalks ‘ 𝐺 ) )  →  ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 17 |  | eqid | ⊢ ( iEdg ‘ 𝐺 )  =  ( iEdg ‘ 𝐺 ) | 
						
							| 18 | 5 17 | clwlkclwwlk2 | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( ∃ 𝑓 𝑓 ( ClWalks ‘ 𝐺 ) ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  ↔  𝑤  ∈  ( ClWWalks ‘ 𝐺 ) ) ) | 
						
							| 19 |  | df-br | ⊢ ( 𝑓 ( ClWalks ‘ 𝐺 ) ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  ↔  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) ) | 
						
							| 20 |  | simpr2 | ⊢ ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  →  𝑤  ∈  Word  ( Vtx ‘ 𝐺 ) ) | 
						
							| 21 |  | simpr3 | ⊢ ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  →  1  ≤  ( ♯ ‘ 𝑤 ) ) | 
						
							| 22 |  | simpl | ⊢ ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  →  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) ) | 
						
							| 23 | 1 | clwlkclwwlkfolem | ⊢ ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  𝐶 ) | 
						
							| 24 | 20 21 22 23 | syl3anc | ⊢ ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  →  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  𝐶 ) | 
						
							| 25 | 23 | 3expa | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  𝐶 ) | 
						
							| 26 |  | ovex | ⊢ ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) )  ∈  V | 
						
							| 27 |  | fveq2 | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( 2nd  ‘ 𝑐 )  =  ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) | 
						
							| 28 |  | 2fveq3 | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( ♯ ‘ ( 2nd  ‘ 𝑐 ) )  =  ( ♯ ‘ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) | 
						
							| 29 | 28 | oveq1d | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( ( ♯ ‘ ( 2nd  ‘ 𝑐 ) )  −  1 )  =  ( ( ♯ ‘ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) )  −  1 ) ) | 
						
							| 30 | 27 29 | oveq12d | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( ( 2nd  ‘ 𝑐 )  prefix  ( ( ♯ ‘ ( 2nd  ‘ 𝑐 ) )  −  1 ) )  =  ( ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  prefix  ( ( ♯ ‘ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) )  −  1 ) ) ) | 
						
							| 31 |  | vex | ⊢ 𝑓  ∈  V | 
						
							| 32 |  | ovex | ⊢ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  ∈  V | 
						
							| 33 | 31 32 | op2nd | ⊢ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  =  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) | 
						
							| 34 | 33 | fveq2i | ⊢ ( ♯ ‘ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) )  =  ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) ) | 
						
							| 35 | 34 | oveq1i | ⊢ ( ( ♯ ‘ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) )  −  1 )  =  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) | 
						
							| 36 | 33 35 | oveq12i | ⊢ ( ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  prefix  ( ( ♯ ‘ ( 2nd  ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) )  −  1 ) )  =  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) ) | 
						
							| 37 | 30 36 | eqtrdi | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( ( 2nd  ‘ 𝑐 )  prefix  ( ( ♯ ‘ ( 2nd  ‘ 𝑐 ) )  −  1 ) )  =  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) ) ) | 
						
							| 38 | 37 2 | fvmptg | ⊢ ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  𝐶  ∧  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) )  ∈  V )  →  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  =  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) ) ) | 
						
							| 39 | 25 26 38 | sylancl | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  =  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) ) ) | 
						
							| 40 |  | wrdlenccats1lenm1 | ⊢ ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  →  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 )  =  ( ♯ ‘ 𝑤 ) ) | 
						
							| 41 | 40 | ad2antrr | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 )  =  ( ♯ ‘ 𝑤 ) ) | 
						
							| 42 | 41 | oveq2d | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ( ♯ ‘ ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) )  −  1 ) )  =  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 43 |  | simpll | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  𝑤  ∈  Word  ( Vtx ‘ 𝐺 ) ) | 
						
							| 44 |  | simpl | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) ) | 
						
							| 45 |  | wrdsymb1 | ⊢ ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 𝑤 ‘ 0 )  ∈  ( Vtx ‘ 𝐺 ) ) | 
						
							| 46 | 44 45 | syl | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( 𝑤 ‘ 0 )  ∈  ( Vtx ‘ 𝐺 ) ) | 
						
							| 47 | 46 | s1cld | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  〈“ ( 𝑤 ‘ 0 ) ”〉  ∈  Word  ( Vtx ‘ 𝐺 ) ) | 
						
							| 48 |  | eqidd | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( ♯ ‘ 𝑤 )  =  ( ♯ ‘ 𝑤 ) ) | 
						
							| 49 |  | pfxccatid | ⊢ ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  〈“ ( 𝑤 ‘ 0 ) ”〉  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  ( ♯ ‘ 𝑤 )  =  ( ♯ ‘ 𝑤 ) )  →  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ♯ ‘ 𝑤 ) )  =  𝑤 ) | 
						
							| 50 | 43 47 48 49 | syl3anc | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  ( ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  prefix  ( ♯ ‘ 𝑤 ) )  =  𝑤 ) | 
						
							| 51 | 39 42 50 | 3eqtrrd | ⊢ ( ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  ∧  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 ) )  →  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) | 
						
							| 52 | 51 | ex | ⊢ ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) | 
						
							| 53 | 52 | 3adant1 | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) | 
						
							| 54 | 53 | ad2antlr | ⊢ ( ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  ∧  𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) | 
						
							| 55 |  | fveq2 | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( 𝐹 ‘ 𝑐 )  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) | 
						
							| 56 | 55 | eqeq2d | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( 𝑤  =  ( 𝐹 ‘ 𝑐 )  ↔  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) | 
						
							| 57 | 56 | imbi2d | ⊢ ( 𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  →  ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 𝑐 ) )  ↔  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) ) | 
						
							| 58 | 57 | adantl | ⊢ ( ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  ∧  𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  →  ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 𝑐 ) )  ↔  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 ) ) ) ) | 
						
							| 59 | 54 58 | mpbird | ⊢ ( ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  ∧  𝑐  =  〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉 )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 60 | 24 59 | rspcimedv | ⊢ ( ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  ∧  ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) ) )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 61 | 60 | ex | ⊢ ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) ) | 
						
							| 62 | 61 | pm2.43b | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 〈 𝑓 ,  ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 ) 〉  ∈  ( ClWalks ‘ 𝐺 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 63 | 19 62 | biimtrid | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 𝑓 ( ClWalks ‘ 𝐺 ) ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 64 | 63 | exlimdv | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( ∃ 𝑓 𝑓 ( ClWalks ‘ 𝐺 ) ( 𝑤  ++  〈“ ( 𝑤 ‘ 0 ) ”〉 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 65 | 18 64 | sylbird | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 66 | 65 | 3expib | ⊢ ( 𝐺  ∈  USPGraph  →  ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) ) | 
						
							| 67 | 66 | com23 | ⊢ ( 𝐺  ∈  USPGraph  →  ( 𝑤  ∈  ( ClWWalks ‘ 𝐺 )  →  ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) ) | 
						
							| 68 | 67 | imp | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  ( ClWWalks ‘ 𝐺 ) )  →  ( ( 𝑤  ∈  Word  ( Vtx ‘ 𝐺 )  ∧  1  ≤  ( ♯ ‘ 𝑤 ) )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 69 | 16 68 | mpd | ⊢ ( ( 𝐺  ∈  USPGraph  ∧  𝑤  ∈  ( ClWWalks ‘ 𝐺 ) )  →  ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) | 
						
							| 70 | 69 | ralrimiva | ⊢ ( 𝐺  ∈  USPGraph  →  ∀ 𝑤  ∈  ( ClWWalks ‘ 𝐺 ) ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) | 
						
							| 71 |  | dffo3 | ⊢ ( 𝐹 : 𝐶 –onto→ ( ClWWalks ‘ 𝐺 )  ↔  ( 𝐹 : 𝐶 ⟶ ( ClWWalks ‘ 𝐺 )  ∧  ∀ 𝑤  ∈  ( ClWWalks ‘ 𝐺 ) ∃ 𝑐  ∈  𝐶 𝑤  =  ( 𝐹 ‘ 𝑐 ) ) ) | 
						
							| 72 | 3 70 71 | sylanbrc | ⊢ ( 𝐺  ∈  USPGraph  →  𝐹 : 𝐶 –onto→ ( ClWWalks ‘ 𝐺 ) ) |