Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
Mirrors > Home > ILE Home > Th. List > stoic4a | GIF version |
Description: Stoic logic Thema 4
version a.
Statement T4 of [Bobzien] p. 117 shows a reconstructed version of Stoic logic thema 4: "When from two assertibles a third follows, and from the third and one (or both) of the two and one (or more) external assertible(s) another follows, then this other follows from the first two and the external(s)." We use 𝜃 to represent the "external" assertibles. This is version a, which is without the phrase "or both"; see stoic4b 1322 for the version with the phrase "or both". (Contributed by David A. Wheeler, 17-Feb-2019.) |
Ref | Expression |
---|---|
stoic4a.1 | ⊢ ((𝜑 ∧ 𝜓) → 𝜒) |
stoic4a.2 | ⊢ ((𝜒 ∧ 𝜑 ∧ 𝜃) → 𝜏) |
Ref | Expression |
---|---|
stoic4a | ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜃) → 𝜏) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | stoic4a.1 | . . 3 ⊢ ((𝜑 ∧ 𝜓) → 𝜒) | |
2 | 1 | 3adant3 924 | . 2 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜃) → 𝜒) |
3 | simp1 904 | . 2 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜃) → 𝜑) | |
4 | simp3 906 | . 2 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜃) → 𝜃) | |
5 | stoic4a.2 | . 2 ⊢ ((𝜒 ∧ 𝜑 ∧ 𝜃) → 𝜏) | |
6 | 2, 3, 4, 5 | syl3anc 1135 | 1 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜃) → 𝜏) |
Colors of variables: wff set class |
Syntax hints: → wi 4 ∧ wa 97 ∧ w3a 885 |
This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 99 ax-ia2 100 ax-ia3 101 |
This theorem depends on definitions: df-bi 110 df-3an 887 |
This theorem is referenced by: (None) |
Copyright terms: Public domain | W3C validator |