Theorem sncld 21979

Description: A singleton is closed in a Hausdorff space. (Contributed by NM, 5-Mar-2007.) (Revised by Mario Carneiro, 24-Aug-2015.)

Hypothesis

Ref	Expression
t1sep.1	⊢ 𝑋 = ∪ 𝐽

Assertion

Ref	Expression
sncld	⊢ ((𝐽 ∈ Haus ∧ 𝑃 ∈ 𝑋) → {𝑃} ∈ (Clsd‘𝐽))

Proof of Theorem sncld

Step	Hyp	Ref	Expression
1		haust1 21960	. 2 ⊢ (𝐽 ∈ Haus → 𝐽 ∈ Fre)
2		t1sep.1	. . 3 ⊢ 𝑋 = ∪ 𝐽
3	2	t1sncld 21934	. 2 ⊢ ((𝐽 ∈ Fre ∧ 𝑃 ∈ 𝑋) → {𝑃} ∈ (Clsd‘𝐽))
4	1, 3	sylan 582	1 ⊢ ((𝐽 ∈ Haus ∧ 𝑃 ∈ 𝑋) → {𝑃} ∈ (Clsd‘𝐽))

Syntax hints:   → wi 4   ∧ wa 398   = wceq 1537   ∈ wcel 2114  {csn 4567  ∪ cuni 4838  ‘cfv 6355  Clsdccld 21624  Frect1 21915  Hauscha 21916

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1796  ax-4 1810  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2116  ax-9 2124  ax-10 2145  ax-11 2161  ax-12 2177  ax-ext 2793  ax-sep 5203  ax-nul 5210  ax-pow 5266  ax-pr 5330  ax-un 7461

This theorem depends on definitions:  df-bi 209  df-an 399  df-or 844  df-3an 1085  df-tru 1540  df-ex 1781  df-nf 1785  df-sb 2070  df-mo 2622  df-eu 2654  df-clab 2800  df-cleq 2814  df-clel 2893  df-nfc 2963  df-ne 3017  df-ral 3143  df-rex 3144  df-rab 3147  df-v 3496  df-sbc 3773  df-dif 3939  df-un 3941  df-in 3943  df-ss 3952  df-nul 4292  df-if 4468  df-pw 4541  df-sn 4568  df-pr 4570  df-op 4574  df-uni 4839  df-br 5067  df-opab 5129  df-mpt 5147  df-id 5460  df-xp 5561  df-rel 5562  df-cnv 5563  df-co 5564  df-dm 5565  df-iota 6314  df-fun 6357  df-fv 6363  df-topgen 16717  df-top 21502  df-topon 21519  df-cld 21627  df-t1 21922  df-haus 21923

This theorem is referenced by:  tgphaus  22725  csscld  23852  clsocv  23853  dvrec  24552  dvexp3  24575  abelth  25029  dvtanlem  34956  sncldre  41324  dirkercncflem2  42409