Theorem metrel 14521

Description: The class of metrics is a relation. (Contributed by Jim Kingdon, 20-Apr-2023.)

Assertion

Ref	Expression
metrel	⊢ Rel Met

Proof of Theorem metrel

Dummy variables 𝑒 𝑑 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		mptrel 4791	. 2 ⊢ Rel (𝑒 ∈ V ↦ {𝑑 ∈ (ℝ ↑𝑚 (𝑒 × 𝑒)) ∣ ∀𝑥 ∈ 𝑒 ∀𝑦 ∈ 𝑒 (((𝑥𝑑𝑦) = 0 ↔ 𝑥 = 𝑦) ∧ ∀𝑧 ∈ 𝑒 (𝑥𝑑𝑦) ≤ ((𝑧𝑑𝑥) + (𝑧𝑑𝑦)))})
2		df-met 14044	. . 3 ⊢ Met = (𝑒 ∈ V ↦ {𝑑 ∈ (ℝ ↑𝑚 (𝑒 × 𝑒)) ∣ ∀𝑥 ∈ 𝑒 ∀𝑦 ∈ 𝑒 (((𝑥𝑑𝑦) = 0 ↔ 𝑥 = 𝑦) ∧ ∀𝑧 ∈ 𝑒 (𝑥𝑑𝑦) ≤ ((𝑧𝑑𝑥) + (𝑧𝑑𝑦)))})
3	2	releqi 4743	. 2 ⊢ (Rel Met ↔ Rel (𝑒 ∈ V ↦ {𝑑 ∈ (ℝ ↑𝑚 (𝑒 × 𝑒)) ∣ ∀𝑥 ∈ 𝑒 ∀𝑦 ∈ 𝑒 (((𝑥𝑑𝑦) = 0 ↔ 𝑥 = 𝑦) ∧ ∀𝑧 ∈ 𝑒 (𝑥𝑑𝑦) ≤ ((𝑧𝑑𝑥) + (𝑧𝑑𝑦)))}))
4	1, 3	mpbir 146	1 ⊢ Rel Met

Syntax hints:   ∧ wa 104   ↔ wb 105   = wceq 1364  ∀wral 2472  {crab 2476  Vcvv 2760   class class class wbr 4030   ↦ cmpt 4091   × cxp 4658  Rel wrel 4665  (class class class)co 5919   ↑_𝑚 cmap 6704  ℝcr 7873  0cc0 7874   + caddc 7877   ≤ cle 8057  Metcmet 14036

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-14 2167  ax-ext 2175  ax-sep 4148  ax-pow 4204  ax-pr 4239

This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-ral 2477  df-rex 2478  df-v 2762  df-un 3158  df-in 3160  df-ss 3167  df-pw 3604  df-sn 3625  df-pr 3626  df-op 3628  df-opab 4092  df-mpt 4093  df-xp 4666  df-rel 4667  df-met 14044

This theorem is referenced by:  metflem  14528  ismet2  14533