Proof 01. 1 ⊢ a ∈ ℝ, hypo. 02. 2 ⊢ b ∈ ℝ, hypo. 03. 3 ⊢ c ∈ ℝ, hypo. 04. 4 ⊢ ¬c = 0, hypo. 05. 3, 4 ⊢ /c ∈ ℝ, rinv_closed 3 4. 06. ⊢ (a + b)/c = (a + b)⋅(/c), rdiv_eq. 07. 1, 2, 3, 4 ⊢ (a + b)⋅(/c) = a⋅(/c) + b⋅(/c), rmul_distr_add 1 2 5. 08. 1, 2, 3, 4 ⊢ (a + b)/c = a⋅(/c) + b⋅(/c), eq_trans 6 7. 09. ⊢ a/c = a⋅(/c), rdiv_eq. 10. ⊢ b/c = b⋅(/c), rdiv_eq. 11. ⊢ a/c + b/c = a⋅(/c) + b⋅(/c), eq_cong_ii 9 10, f x y = x + y. 12. 1, 2, 3, 4 ⊢ (a + b)/c = a/c + b/c, eq_trans_rr 8 11. rdiv_dist_add. ⊢ a ∈ ℝ → b ∈ ℝ → c ∈ ℝ → ¬c = 0 → (a + b)/c = a/c + b/c, subj_intro_iv 12.
Dependencies
The given proof depends on six axioms:
eq_refl, eq_subst, radd_closed, rinv_closed, rmul_comm, rmul_distl_add.