Theorem sstpr 3845

Description: The subsets of a triple. (Contributed by Jim Kingdon, 11-Aug-2018.)

Assertion

Ref	Expression
sstpr	⊢ ((((𝐴 = ∅ ∨ 𝐴 = {𝐵}) ∨ (𝐴 = {𝐶} ∨ 𝐴 = {𝐵, 𝐶})) ∨ ((𝐴 = {𝐷} ∨ 𝐴 = {𝐵, 𝐷}) ∨ (𝐴 = {𝐶, 𝐷} ∨ 𝐴 = {𝐵, 𝐶, 𝐷}))) → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})

Proof of Theorem sstpr

Step	Hyp	Ref	Expression
1		ssprr 3844	. . 3 ⊢ (((𝐴 = ∅ ∨ 𝐴 = {𝐵}) ∨ (𝐴 = {𝐶} ∨ 𝐴 = {𝐵, 𝐶})) → 𝐴 ⊆ {𝐵, 𝐶})
2		prsstp12 3831	. . 3 ⊢ {𝐵, 𝐶} ⊆ {𝐵, 𝐶, 𝐷}
3	1, 2	sstrdi 3240	. 2 ⊢ (((𝐴 = ∅ ∨ 𝐴 = {𝐵}) ∨ (𝐴 = {𝐶} ∨ 𝐴 = {𝐵, 𝐶})) → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
4		snsstp3 3830	. . . . 5 ⊢ {𝐷} ⊆ {𝐵, 𝐶, 𝐷}
5		sseq1 3251	. . . . 5 ⊢ (𝐴 = {𝐷} → (𝐴 ⊆ {𝐵, 𝐶, 𝐷} ↔ {𝐷} ⊆ {𝐵, 𝐶, 𝐷}))
6	4, 5	mpbiri 168	. . . 4 ⊢ (𝐴 = {𝐷} → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
7		prsstp13 3832	. . . . 5 ⊢ {𝐵, 𝐷} ⊆ {𝐵, 𝐶, 𝐷}
8		sseq1 3251	. . . . 5 ⊢ (𝐴 = {𝐵, 𝐷} → (𝐴 ⊆ {𝐵, 𝐶, 𝐷} ↔ {𝐵, 𝐷} ⊆ {𝐵, 𝐶, 𝐷}))
9	7, 8	mpbiri 168	. . . 4 ⊢ (𝐴 = {𝐵, 𝐷} → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
10	6, 9	jaoi 724	. . 3 ⊢ ((𝐴 = {𝐷} ∨ 𝐴 = {𝐵, 𝐷}) → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
11		prsstp23 3833	. . . . 5 ⊢ {𝐶, 𝐷} ⊆ {𝐵, 𝐶, 𝐷}
12		sseq1 3251	. . . . 5 ⊢ (𝐴 = {𝐶, 𝐷} → (𝐴 ⊆ {𝐵, 𝐶, 𝐷} ↔ {𝐶, 𝐷} ⊆ {𝐵, 𝐶, 𝐷}))
13	11, 12	mpbiri 168	. . . 4 ⊢ (𝐴 = {𝐶, 𝐷} → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
14		eqimss 3282	. . . 4 ⊢ (𝐴 = {𝐵, 𝐶, 𝐷} → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
15	13, 14	jaoi 724	. . 3 ⊢ ((𝐴 = {𝐶, 𝐷} ∨ 𝐴 = {𝐵, 𝐶, 𝐷}) → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
16	10, 15	jaoi 724	. 2 ⊢ (((𝐴 = {𝐷} ∨ 𝐴 = {𝐵, 𝐷}) ∨ (𝐴 = {𝐶, 𝐷} ∨ 𝐴 = {𝐵, 𝐶, 𝐷})) → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})
17	3, 16	jaoi 724	1 ⊢ ((((𝐴 = ∅ ∨ 𝐴 = {𝐵}) ∨ (𝐴 = {𝐶} ∨ 𝐴 = {𝐵, 𝐶})) ∨ ((𝐴 = {𝐷} ∨ 𝐴 = {𝐵, 𝐷}) ∨ (𝐴 = {𝐶, 𝐷} ∨ 𝐴 = {𝐵, 𝐶, 𝐷}))) → 𝐴 ⊆ {𝐵, 𝐶, 𝐷})

Syntax hints:   → wi 4   ∨ wo 716   = wceq 1398   ⊆ wss 3201  ∅c0 3496  {csn 3673  {cpr 3674  {ctp 3675

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-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2213

This theorem depends on definitions:  df-bi 117  df-3or 1006  df-tru 1401  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-v 2805  df-dif 3203  df-un 3205  df-in 3207  df-ss 3214  df-nul 3497  df-sn 3679  df-pr 3680  df-tp 3681

This theorem is referenced by:  pwtpss  3895