| Step | Hyp | Ref | Expression | 
						
							| 1 |  | xp1st | ⊢ ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  →  ( 1st  ‘ 𝐴 )  ∈  ( 𝑈  ×  𝑉 ) ) | 
						
							| 2 | 1 | ad2antrl | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  ( 1st  ‘ 𝐴 )  ∈  ( 𝑈  ×  𝑉 ) ) | 
						
							| 3 |  | 3simpa | ⊢ ( ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 )  →  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌 ) ) | 
						
							| 4 | 3 | adantl | ⊢ ( ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) )  →  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌 ) ) | 
						
							| 5 | 4 | adantl | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌 ) ) | 
						
							| 6 |  | eqopi | ⊢ ( ( ( 1st  ‘ 𝐴 )  ∈  ( 𝑈  ×  𝑉 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌 ) )  →  ( 1st  ‘ 𝐴 )  =  〈 𝑋 ,  𝑌 〉 ) | 
						
							| 7 | 2 5 6 | syl2anc | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  ( 1st  ‘ 𝐴 )  =  〈 𝑋 ,  𝑌 〉 ) | 
						
							| 8 |  | simprr3 | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  ( 2nd  ‘ 𝐴 )  =  𝑍 ) | 
						
							| 9 | 7 8 | jca | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  ( ( 1st  ‘ 𝐴 )  =  〈 𝑋 ,  𝑌 〉  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) | 
						
							| 10 |  | df-ot | ⊢ 〈 𝑋 ,  𝑌 ,  𝑍 〉  =  〈 〈 𝑋 ,  𝑌 〉 ,  𝑍 〉 | 
						
							| 11 | 10 | eqeq2i | ⊢ ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  ↔  𝐴  =  〈 〈 𝑋 ,  𝑌 〉 ,  𝑍 〉 ) | 
						
							| 12 |  | eqop | ⊢ ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  →  ( 𝐴  =  〈 〈 𝑋 ,  𝑌 〉 ,  𝑍 〉  ↔  ( ( 1st  ‘ 𝐴 )  =  〈 𝑋 ,  𝑌 〉  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) ) | 
						
							| 13 | 11 12 | bitrid | ⊢ ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  →  ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  ↔  ( ( 1st  ‘ 𝐴 )  =  〈 𝑋 ,  𝑌 〉  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) ) | 
						
							| 14 | 13 | ad2antrl | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  ↔  ( ( 1st  ‘ 𝐴 )  =  〈 𝑋 ,  𝑌 〉  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) ) | 
						
							| 15 | 9 14 | mpbird | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) )  →  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 ) | 
						
							| 16 |  | opelxpi | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉 )  →  〈 𝑋 ,  𝑌 〉  ∈  ( 𝑈  ×  𝑉 ) ) | 
						
							| 17 | 16 | 3adant3 | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  〈 𝑋 ,  𝑌 〉  ∈  ( 𝑈  ×  𝑉 ) ) | 
						
							| 18 |  | simp3 | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  𝑍  ∈  𝑊 ) | 
						
							| 19 | 17 18 | opelxpd | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  〈 〈 𝑋 ,  𝑌 〉 ,  𝑍 〉  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 ) ) | 
						
							| 20 | 10 19 | eqeltrid | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  〈 𝑋 ,  𝑌 ,  𝑍 〉  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 ) ) | 
						
							| 21 | 20 | adantr | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  〈 𝑋 ,  𝑌 ,  𝑍 〉  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 ) ) | 
						
							| 22 |  | eleq1 | ⊢ ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  →  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ↔  〈 𝑋 ,  𝑌 ,  𝑍 〉  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 ) ) ) | 
						
							| 23 | 22 | adantl | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ↔  〈 𝑋 ,  𝑌 ,  𝑍 〉  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 ) ) ) | 
						
							| 24 | 21 23 | mpbird | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 ) ) | 
						
							| 25 |  | 2fveq3 | ⊢ ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  →  ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  ( 1st  ‘ ( 1st  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 ) ) ) | 
						
							| 26 |  | ot1stg | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  ( 1st  ‘ ( 1st  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 ) )  =  𝑋 ) | 
						
							| 27 | 25 26 | sylan9eqr | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋 ) | 
						
							| 28 |  | 2fveq3 | ⊢ ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  →  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  ( 2nd  ‘ ( 1st  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 ) ) ) | 
						
							| 29 |  | ot2ndg | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  ( 2nd  ‘ ( 1st  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 ) )  =  𝑌 ) | 
						
							| 30 | 28 29 | sylan9eqr | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌 ) | 
						
							| 31 |  | fveq2 | ⊢ ( 𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉  →  ( 2nd  ‘ 𝐴 )  =  ( 2nd  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 ) ) | 
						
							| 32 |  | ot3rdg | ⊢ ( 𝑍  ∈  𝑊  →  ( 2nd  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 )  =  𝑍 ) | 
						
							| 33 | 32 | 3ad2ant3 | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  ( 2nd  ‘ 〈 𝑋 ,  𝑌 ,  𝑍 〉 )  =  𝑍 ) | 
						
							| 34 | 31 33 | sylan9eqr | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  ( 2nd  ‘ 𝐴 )  =  𝑍 ) | 
						
							| 35 | 27 30 34 | 3jca | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) | 
						
							| 36 | 24 35 | jca | ⊢ ( ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  ∧  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 )  →  ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) ) ) | 
						
							| 37 | 15 36 | impbida | ⊢ ( ( 𝑋  ∈  𝑈  ∧  𝑌  ∈  𝑉  ∧  𝑍  ∈  𝑊 )  →  ( ( 𝐴  ∈  ( ( 𝑈  ×  𝑉 )  ×  𝑊 )  ∧  ( ( 1st  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑋  ∧  ( 2nd  ‘ ( 1st  ‘ 𝐴 ) )  =  𝑌  ∧  ( 2nd  ‘ 𝐴 )  =  𝑍 ) )  ↔  𝐴  =  〈 𝑋 ,  𝑌 ,  𝑍 〉 ) ) |