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Mirrors > Home > MPE Home > Th. List > sylan9ss | Structured version Visualization version GIF version |
Description: A subclass transitivity deduction. (Contributed by NM, 27-Sep-2004.) (Proof shortened by Andrew Salmon, 14-Jun-2011.) |
Ref | Expression |
---|---|
sylan9ss.1 | ⊢ (𝜑 → 𝐴 ⊆ 𝐵) |
sylan9ss.2 | ⊢ (𝜓 → 𝐵 ⊆ 𝐶) |
Ref | Expression |
---|---|
sylan9ss | ⊢ ((𝜑 ∧ 𝜓) → 𝐴 ⊆ 𝐶) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sylan9ss.1 | . 2 ⊢ (𝜑 → 𝐴 ⊆ 𝐵) | |
2 | sylan9ss.2 | . 2 ⊢ (𝜓 → 𝐵 ⊆ 𝐶) | |
3 | sstr 3990 | . 2 ⊢ ((𝐴 ⊆ 𝐵 ∧ 𝐵 ⊆ 𝐶) → 𝐴 ⊆ 𝐶) | |
4 | 1, 2, 3 | syl2an 596 | 1 ⊢ ((𝜑 ∧ 𝜓) → 𝐴 ⊆ 𝐶) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 396 ⊆ wss 3948 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1797 ax-4 1811 ax-5 1913 ax-6 1971 ax-7 2011 ax-8 2108 ax-9 2116 ax-ext 2703 |
This theorem depends on definitions: df-bi 206 df-an 397 df-tru 1544 df-ex 1782 df-sb 2068 df-clab 2710 df-cleq 2724 df-clel 2810 df-v 3476 df-in 3955 df-ss 3965 |
This theorem is referenced by: sylan9ssr 3996 psstr 4104 unss12 4182 ss2in 4236 ssdisj 4459 relrelss 6272 funssxp 6746 axdc3lem 10447 tskuni 10780 rtrclreclem4 15010 tsmsxp 23666 shslubi 30676 chlej12i 30766 insiga 33204 fnetr 35322 pcl0bN 38880 brtrclfv2 42560 |
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