Proof 01. 1 ⊢ a ∈ ℝ, hypo. 02. ⊢ 1 ∈ ℝ, calc. 03. 1 ⊢ a⋅1 = a, rmul_neutr 1. 04. 1 ⊢ 1⋅a = a⋅1, rmul_comm 2 1. 05. 1 ⊢ 1⋅a = a, eq_trans 4 3. rmul_neutl. ⊢ a ∈ ℝ → 1⋅a = a, subj_intro 5.
Dependencies
The given proof depends on four axioms:
eq_refl, eq_subst, rmul_comm, rmul_neutr.