Theorem reliun 5803

Description: An indexed union is a relation iff each member of its indexed family is a relation. (Contributed by NM, 19-Dec-2008.) (Proof shortened by SN, 2-Feb-2025.)

Assertion

Ref	Expression
reliun	⊢ (Rel ∪ 𝑥 ∈ 𝐴 𝐵 ↔ ∀𝑥 ∈ 𝐴 Rel 𝐵)

Proof of Theorem reliun

Step	Hyp	Ref	Expression
1		iunss 5009	. 2 ⊢ (∪ 𝑥 ∈ 𝐴 𝐵 ⊆ (V × V) ↔ ∀𝑥 ∈ 𝐴 𝐵 ⊆ (V × V))
2		df-rel 5668	. 2 ⊢ (Rel ∪ 𝑥 ∈ 𝐴 𝐵 ↔ ∪ 𝑥 ∈ 𝐴 𝐵 ⊆ (V × V))
3		df-rel 5668	. . 3 ⊢ (Rel 𝐵 ↔ 𝐵 ⊆ (V × V))
4	3	ralbii 3111	. 2 ⊢ (∀𝑥 ∈ 𝐴 Rel 𝐵 ↔ ∀𝑥 ∈ 𝐴 𝐵 ⊆ (V × V))
5	1, 2, 4	3bitr4i 306	1 ⊢ (Rel ∪ 𝑥 ∈ 𝐴 𝐵 ↔ ∀𝑥 ∈ 𝐴 Rel 𝐵)

This proof depends on syntax axioms:   ↔ wb 209  ∀wral 3079  Vcvv 3455   ⊆ wss 3905  ∪ ciun 4956   × cxp 5659  Rel wrel 5666

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1825  ax-4 1839  ax-5 1940  ax-6 1997  ax-7 2038  ax-8 2145  ax-9 2153  ax-11 2192  ax-ext 2735

This proof depends on definitions:  df-bi 210  df-an 401  df-tru 1573  df-ex 1810  df-sb 2097  df-clab 2742  df-cleq 2755  df-clel 2838  df-ral 3080  df-rex 3090  df-v 3457  df-ss 3922  df-iun 4958  df-rel 5668

This theorem is used by:  reluni  5805  eliunxp  5823  opeliunxp2  5824  dfco2  6246  coiun  6258  fvn0ssdmfun  7069  opeliunxp2f  8202  fsumcom2  15830  fprodcom2  16043  imasaddfnlem  17586  imasvscafn  17595  gsum2d2lem  20047  gsum2d2  20048  gsumcom2  20049  dprd2d2  20120  cnextrel  24229  reldv  26038  dfcnv2  33029  gsumpart  33392  gsumwrd2dccat  33407  cvmliftlem1  35785  cnviun  44404  coiun1  44406  eliunxp2  49142