Description: Reverse closure for the first argument of pGrp . (Contributed by Mario Carneiro, 15-Jan-2015)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | pgpprm | ⊢ ( 𝑃 pGrp 𝐺 → 𝑃 ∈ ℙ ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | eqid | ⊢ ( Base ‘ 𝐺 ) = ( Base ‘ 𝐺 ) | |
| 2 | eqid | ⊢ ( od ‘ 𝐺 ) = ( od ‘ 𝐺 ) | |
| 3 | 1 2 | ispgp | ⊢ ( 𝑃 pGrp 𝐺 ↔ ( 𝑃 ∈ ℙ ∧ 𝐺 ∈ Grp ∧ ∀ 𝑥 ∈ ( Base ‘ 𝐺 ) ∃ 𝑛 ∈ ℕ0 ( ( od ‘ 𝐺 ) ‘ 𝑥 ) = ( 𝑃 ↑ 𝑛 ) ) ) | 
| 4 | 3 | simp1bi | ⊢ ( 𝑃 pGrp 𝐺 → 𝑃 ∈ ℙ ) |