| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐷  ∈  ( PsMet ‘ 𝑋 ) ) | 
						
							| 2 |  | metidss | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  ( ~Met ‘ 𝐷 )  ⊆  ( 𝑋  ×  𝑋 ) ) | 
						
							| 3 |  | dmss | ⊢ ( ( ~Met ‘ 𝐷 )  ⊆  ( 𝑋  ×  𝑋 )  →  dom  ( ~Met ‘ 𝐷 )  ⊆  dom  ( 𝑋  ×  𝑋 ) ) | 
						
							| 4 | 2 3 | syl | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  dom  ( ~Met ‘ 𝐷 )  ⊆  dom  ( 𝑋  ×  𝑋 ) ) | 
						
							| 5 |  | dmxpid | ⊢ dom  ( 𝑋  ×  𝑋 )  =  𝑋 | 
						
							| 6 | 4 5 | sseqtrdi | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  dom  ( ~Met ‘ 𝐷 )  ⊆  𝑋 ) | 
						
							| 7 | 1 6 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  dom  ( ~Met ‘ 𝐷 )  ⊆  𝑋 ) | 
						
							| 8 |  | xpss | ⊢ ( 𝑋  ×  𝑋 )  ⊆  ( V  ×  V ) | 
						
							| 9 | 2 8 | sstrdi | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  ( ~Met ‘ 𝐷 )  ⊆  ( V  ×  V ) ) | 
						
							| 10 |  | df-rel | ⊢ ( Rel  ( ~Met ‘ 𝐷 )  ↔  ( ~Met ‘ 𝐷 )  ⊆  ( V  ×  V ) ) | 
						
							| 11 | 9 10 | sylibr | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  Rel  ( ~Met ‘ 𝐷 ) ) | 
						
							| 12 | 1 11 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  Rel  ( ~Met ‘ 𝐷 ) ) | 
						
							| 13 |  | simprl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐴 ( ~Met ‘ 𝐷 ) 𝐵 ) | 
						
							| 14 |  | releldm | ⊢ ( ( Rel  ( ~Met ‘ 𝐷 )  ∧  𝐴 ( ~Met ‘ 𝐷 ) 𝐵 )  →  𝐴  ∈  dom  ( ~Met ‘ 𝐷 ) ) | 
						
							| 15 | 12 13 14 | syl2anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐴  ∈  dom  ( ~Met ‘ 𝐷 ) ) | 
						
							| 16 | 7 15 | sseldd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐴  ∈  𝑋 ) | 
						
							| 17 |  | simprr | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) | 
						
							| 18 |  | releldm | ⊢ ( ( Rel  ( ~Met ‘ 𝐷 )  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 )  →  𝐸  ∈  dom  ( ~Met ‘ 𝐷 ) ) | 
						
							| 19 | 12 17 18 | syl2anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐸  ∈  dom  ( ~Met ‘ 𝐷 ) ) | 
						
							| 20 | 7 19 | sseldd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐸  ∈  𝑋 ) | 
						
							| 21 |  | psmetsym | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  𝐴  ∈  𝑋  ∧  𝐸  ∈  𝑋 )  →  ( 𝐴 𝐷 𝐸 )  =  ( 𝐸 𝐷 𝐴 ) ) | 
						
							| 22 | 1 16 20 21 | syl3anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐸 )  =  ( 𝐸 𝐷 𝐴 ) ) | 
						
							| 23 |  | psmetf | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  𝐷 : ( 𝑋  ×  𝑋 ) ⟶ ℝ* ) | 
						
							| 24 | 23 | fovcdmda | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐸  ∈  𝑋  ∧  𝐴  ∈  𝑋 ) )  →  ( 𝐸 𝐷 𝐴 )  ∈  ℝ* ) | 
						
							| 25 | 1 20 16 24 | syl12anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐸 𝐷 𝐴 )  ∈  ℝ* ) | 
						
							| 26 | 22 25 | eqeltrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐸 )  ∈  ℝ* ) | 
						
							| 27 |  | rnss | ⊢ ( ( ~Met ‘ 𝐷 )  ⊆  ( 𝑋  ×  𝑋 )  →  ran  ( ~Met ‘ 𝐷 )  ⊆  ran  ( 𝑋  ×  𝑋 ) ) | 
						
							| 28 | 2 27 | syl | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  ran  ( ~Met ‘ 𝐷 )  ⊆  ran  ( 𝑋  ×  𝑋 ) ) | 
						
							| 29 |  | rnxpid | ⊢ ran  ( 𝑋  ×  𝑋 )  =  𝑋 | 
						
							| 30 | 28 29 | sseqtrdi | ⊢ ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  →  ran  ( ~Met ‘ 𝐷 )  ⊆  𝑋 ) | 
						
							| 31 | 1 30 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ran  ( ~Met ‘ 𝐷 )  ⊆  𝑋 ) | 
						
							| 32 |  | relelrn | ⊢ ( ( Rel  ( ~Met ‘ 𝐷 )  ∧  𝐴 ( ~Met ‘ 𝐷 ) 𝐵 )  →  𝐵  ∈  ran  ( ~Met ‘ 𝐷 ) ) | 
						
							| 33 | 12 13 32 | syl2anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐵  ∈  ran  ( ~Met ‘ 𝐷 ) ) | 
						
							| 34 | 31 33 | sseldd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐵  ∈  𝑋 ) | 
						
							| 35 | 23 | fovcdmda | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐵  ∈  𝑋  ∧  𝐸  ∈  𝑋 ) )  →  ( 𝐵 𝐷 𝐸 )  ∈  ℝ* ) | 
						
							| 36 | 1 34 20 35 | syl12anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐸 )  ∈  ℝ* ) | 
						
							| 37 |  | relelrn | ⊢ ( ( Rel  ( ~Met ‘ 𝐷 )  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 )  →  𝐹  ∈  ran  ( ~Met ‘ 𝐷 ) ) | 
						
							| 38 | 12 17 37 | syl2anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐹  ∈  ran  ( ~Met ‘ 𝐷 ) ) | 
						
							| 39 | 31 38 | sseldd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  𝐹  ∈  𝑋 ) | 
						
							| 40 |  | psmetsym | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  𝐹  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  →  ( 𝐹 𝐷 𝐵 )  =  ( 𝐵 𝐷 𝐹 ) ) | 
						
							| 41 | 1 39 34 40 | syl3anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐹 𝐷 𝐵 )  =  ( 𝐵 𝐷 𝐹 ) ) | 
						
							| 42 | 23 | fovcdmda | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐹  ∈  𝑋  ∧  𝐵  ∈  𝑋 ) )  →  ( 𝐹 𝐷 𝐵 )  ∈  ℝ* ) | 
						
							| 43 | 1 39 34 42 | syl12anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐹 𝐷 𝐵 )  ∈  ℝ* ) | 
						
							| 44 | 41 43 | eqeltrrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐹 )  ∈  ℝ* ) | 
						
							| 45 |  | psmettri2 | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐵  ∈  𝑋  ∧  𝐴  ∈  𝑋  ∧  𝐸  ∈  𝑋 ) )  →  ( 𝐴 𝐷 𝐸 )  ≤  ( ( 𝐵 𝐷 𝐴 )  +𝑒  ( 𝐵 𝐷 𝐸 ) ) ) | 
						
							| 46 | 1 34 16 20 45 | syl13anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐸 )  ≤  ( ( 𝐵 𝐷 𝐴 )  +𝑒  ( 𝐵 𝐷 𝐸 ) ) ) | 
						
							| 47 |  | psmetsym | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 )  →  ( 𝐴 𝐷 𝐵 )  =  ( 𝐵 𝐷 𝐴 ) ) | 
						
							| 48 | 1 16 34 47 | syl3anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐵 )  =  ( 𝐵 𝐷 𝐴 ) ) | 
						
							| 49 | 16 34 | jca | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 ) ) | 
						
							| 50 |  | metidv | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 ) )  →  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ↔  ( 𝐴 𝐷 𝐵 )  =  0 ) ) | 
						
							| 51 | 50 | biimpa | ⊢ ( ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋 ) )  ∧  𝐴 ( ~Met ‘ 𝐷 ) 𝐵 )  →  ( 𝐴 𝐷 𝐵 )  =  0 ) | 
						
							| 52 | 1 49 13 51 | syl21anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐵 )  =  0 ) | 
						
							| 53 | 48 52 | eqtr3d | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐴 )  =  0 ) | 
						
							| 54 | 53 | oveq1d | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐵 𝐷 𝐴 )  +𝑒  ( 𝐵 𝐷 𝐸 ) )  =  ( 0  +𝑒  ( 𝐵 𝐷 𝐸 ) ) ) | 
						
							| 55 |  | xaddlid | ⊢ ( ( 𝐵 𝐷 𝐸 )  ∈  ℝ*  →  ( 0  +𝑒  ( 𝐵 𝐷 𝐸 ) )  =  ( 𝐵 𝐷 𝐸 ) ) | 
						
							| 56 | 36 55 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 0  +𝑒  ( 𝐵 𝐷 𝐸 ) )  =  ( 𝐵 𝐷 𝐸 ) ) | 
						
							| 57 | 54 56 | eqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐵 𝐷 𝐴 )  +𝑒  ( 𝐵 𝐷 𝐸 ) )  =  ( 𝐵 𝐷 𝐸 ) ) | 
						
							| 58 | 46 57 | breqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐸 )  ≤  ( 𝐵 𝐷 𝐸 ) ) | 
						
							| 59 |  | psmettri2 | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐹  ∈  𝑋  ∧  𝐵  ∈  𝑋  ∧  𝐸  ∈  𝑋 ) )  →  ( 𝐵 𝐷 𝐸 )  ≤  ( ( 𝐹 𝐷 𝐵 )  +𝑒  ( 𝐹 𝐷 𝐸 ) ) ) | 
						
							| 60 | 1 39 34 20 59 | syl13anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐸 )  ≤  ( ( 𝐹 𝐷 𝐵 )  +𝑒  ( 𝐹 𝐷 𝐸 ) ) ) | 
						
							| 61 |  | psmetsym | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  𝐹  ∈  𝑋  ∧  𝐸  ∈  𝑋 )  →  ( 𝐹 𝐷 𝐸 )  =  ( 𝐸 𝐷 𝐹 ) ) | 
						
							| 62 | 1 39 20 61 | syl3anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐹 𝐷 𝐸 )  =  ( 𝐸 𝐷 𝐹 ) ) | 
						
							| 63 | 20 39 | jca | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐸  ∈  𝑋  ∧  𝐹  ∈  𝑋 ) ) | 
						
							| 64 |  | metidv | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐸  ∈  𝑋  ∧  𝐹  ∈  𝑋 ) )  →  ( 𝐸 ( ~Met ‘ 𝐷 ) 𝐹  ↔  ( 𝐸 𝐷 𝐹 )  =  0 ) ) | 
						
							| 65 | 64 | biimpa | ⊢ ( ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐸  ∈  𝑋  ∧  𝐹  ∈  𝑋 ) )  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 )  →  ( 𝐸 𝐷 𝐹 )  =  0 ) | 
						
							| 66 | 1 63 17 65 | syl21anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐸 𝐷 𝐹 )  =  0 ) | 
						
							| 67 | 62 66 | eqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐹 𝐷 𝐸 )  =  0 ) | 
						
							| 68 | 67 | oveq2d | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐹 𝐷 𝐵 )  +𝑒  ( 𝐹 𝐷 𝐸 ) )  =  ( ( 𝐹 𝐷 𝐵 )  +𝑒  0 ) ) | 
						
							| 69 |  | xaddrid | ⊢ ( ( 𝐹 𝐷 𝐵 )  ∈  ℝ*  →  ( ( 𝐹 𝐷 𝐵 )  +𝑒  0 )  =  ( 𝐹 𝐷 𝐵 ) ) | 
						
							| 70 | 43 69 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐹 𝐷 𝐵 )  +𝑒  0 )  =  ( 𝐹 𝐷 𝐵 ) ) | 
						
							| 71 | 68 70 41 | 3eqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐹 𝐷 𝐵 )  +𝑒  ( 𝐹 𝐷 𝐸 ) )  =  ( 𝐵 𝐷 𝐹 ) ) | 
						
							| 72 | 60 71 | breqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐸 )  ≤  ( 𝐵 𝐷 𝐹 ) ) | 
						
							| 73 | 26 36 44 58 72 | xrletrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐸 )  ≤  ( 𝐵 𝐷 𝐹 ) ) | 
						
							| 74 | 23 | fovcdmda | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴  ∈  𝑋  ∧  𝐹  ∈  𝑋 ) )  →  ( 𝐴 𝐷 𝐹 )  ∈  ℝ* ) | 
						
							| 75 | 1 16 39 74 | syl12anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐹 )  ∈  ℝ* ) | 
						
							| 76 |  | psmettri2 | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴  ∈  𝑋  ∧  𝐵  ∈  𝑋  ∧  𝐹  ∈  𝑋 ) )  →  ( 𝐵 𝐷 𝐹 )  ≤  ( ( 𝐴 𝐷 𝐵 )  +𝑒  ( 𝐴 𝐷 𝐹 ) ) ) | 
						
							| 77 | 1 16 34 39 76 | syl13anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐹 )  ≤  ( ( 𝐴 𝐷 𝐵 )  +𝑒  ( 𝐴 𝐷 𝐹 ) ) ) | 
						
							| 78 | 52 | oveq1d | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐴 𝐷 𝐵 )  +𝑒  ( 𝐴 𝐷 𝐹 ) )  =  ( 0  +𝑒  ( 𝐴 𝐷 𝐹 ) ) ) | 
						
							| 79 |  | xaddlid | ⊢ ( ( 𝐴 𝐷 𝐹 )  ∈  ℝ*  →  ( 0  +𝑒  ( 𝐴 𝐷 𝐹 ) )  =  ( 𝐴 𝐷 𝐹 ) ) | 
						
							| 80 | 75 79 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 0  +𝑒  ( 𝐴 𝐷 𝐹 ) )  =  ( 𝐴 𝐷 𝐹 ) ) | 
						
							| 81 | 78 80 | eqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐴 𝐷 𝐵 )  +𝑒  ( 𝐴 𝐷 𝐹 ) )  =  ( 𝐴 𝐷 𝐹 ) ) | 
						
							| 82 | 77 81 | breqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐹 )  ≤  ( 𝐴 𝐷 𝐹 ) ) | 
						
							| 83 |  | psmettri2 | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐸  ∈  𝑋  ∧  𝐴  ∈  𝑋  ∧  𝐹  ∈  𝑋 ) )  →  ( 𝐴 𝐷 𝐹 )  ≤  ( ( 𝐸 𝐷 𝐴 )  +𝑒  ( 𝐸 𝐷 𝐹 ) ) ) | 
						
							| 84 | 1 20 16 39 83 | syl13anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐹 )  ≤  ( ( 𝐸 𝐷 𝐴 )  +𝑒  ( 𝐸 𝐷 𝐹 ) ) ) | 
						
							| 85 |  | xaddrid | ⊢ ( ( 𝐸 𝐷 𝐴 )  ∈  ℝ*  →  ( ( 𝐸 𝐷 𝐴 )  +𝑒  0 )  =  ( 𝐸 𝐷 𝐴 ) ) | 
						
							| 86 | 25 85 | syl | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐸 𝐷 𝐴 )  +𝑒  0 )  =  ( 𝐸 𝐷 𝐴 ) ) | 
						
							| 87 | 66 | oveq2d | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐸 𝐷 𝐴 )  +𝑒  ( 𝐸 𝐷 𝐹 ) )  =  ( ( 𝐸 𝐷 𝐴 )  +𝑒  0 ) ) | 
						
							| 88 | 86 87 22 | 3eqtr4d | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐸 𝐷 𝐴 )  +𝑒  ( 𝐸 𝐷 𝐹 ) )  =  ( 𝐴 𝐷 𝐸 ) ) | 
						
							| 89 | 84 88 | breqtrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐹 )  ≤  ( 𝐴 𝐷 𝐸 ) ) | 
						
							| 90 | 44 75 26 82 89 | xrletrd | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐵 𝐷 𝐹 )  ≤  ( 𝐴 𝐷 𝐸 ) ) | 
						
							| 91 |  | xrletri3 | ⊢ ( ( ( 𝐴 𝐷 𝐸 )  ∈  ℝ*  ∧  ( 𝐵 𝐷 𝐹 )  ∈  ℝ* )  →  ( ( 𝐴 𝐷 𝐸 )  =  ( 𝐵 𝐷 𝐹 )  ↔  ( ( 𝐴 𝐷 𝐸 )  ≤  ( 𝐵 𝐷 𝐹 )  ∧  ( 𝐵 𝐷 𝐹 )  ≤  ( 𝐴 𝐷 𝐸 ) ) ) ) | 
						
							| 92 | 26 44 91 | syl2anc | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( ( 𝐴 𝐷 𝐸 )  =  ( 𝐵 𝐷 𝐹 )  ↔  ( ( 𝐴 𝐷 𝐸 )  ≤  ( 𝐵 𝐷 𝐹 )  ∧  ( 𝐵 𝐷 𝐹 )  ≤  ( 𝐴 𝐷 𝐸 ) ) ) ) | 
						
							| 93 | 73 90 92 | mpbir2and | ⊢ ( ( 𝐷  ∈  ( PsMet ‘ 𝑋 )  ∧  ( 𝐴 ( ~Met ‘ 𝐷 ) 𝐵  ∧  𝐸 ( ~Met ‘ 𝐷 ) 𝐹 ) )  →  ( 𝐴 𝐷 𝐸 )  =  ( 𝐵 𝐷 𝐹 ) ) |