Step |
Hyp |
Ref |
Expression |
1 |
|
readdid1addid2d.a |
⊢ ( 𝜑 → 𝐴 ∈ ℝ ) |
2 |
|
readdid1addid2d.b |
⊢ ( 𝜑 → 𝐵 ∈ ℝ ) |
3 |
|
readdid1addid2d.1 |
⊢ ( 𝜑 → ( 𝐵 + 𝐴 ) = 𝐵 ) |
4 |
2
|
adantr |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → 𝐵 ∈ ℝ ) |
5 |
4
|
recnd |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → 𝐵 ∈ ℂ ) |
6 |
1
|
adantr |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → 𝐴 ∈ ℝ ) |
7 |
6
|
recnd |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → 𝐴 ∈ ℂ ) |
8 |
|
simpr |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → 𝐶 ∈ ℝ ) |
9 |
8
|
recnd |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → 𝐶 ∈ ℂ ) |
10 |
5 7 9
|
addassd |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( ( 𝐵 + 𝐴 ) + 𝐶 ) = ( 𝐵 + ( 𝐴 + 𝐶 ) ) ) |
11 |
3
|
adantr |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( 𝐵 + 𝐴 ) = 𝐵 ) |
12 |
11
|
oveq1d |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( ( 𝐵 + 𝐴 ) + 𝐶 ) = ( 𝐵 + 𝐶 ) ) |
13 |
10 12
|
eqtr3d |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( 𝐵 + ( 𝐴 + 𝐶 ) ) = ( 𝐵 + 𝐶 ) ) |
14 |
6 8
|
readdcld |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( 𝐴 + 𝐶 ) ∈ ℝ ) |
15 |
|
readdcan |
⊢ ( ( ( 𝐴 + 𝐶 ) ∈ ℝ ∧ 𝐶 ∈ ℝ ∧ 𝐵 ∈ ℝ ) → ( ( 𝐵 + ( 𝐴 + 𝐶 ) ) = ( 𝐵 + 𝐶 ) ↔ ( 𝐴 + 𝐶 ) = 𝐶 ) ) |
16 |
14 8 4 15
|
syl3anc |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( ( 𝐵 + ( 𝐴 + 𝐶 ) ) = ( 𝐵 + 𝐶 ) ↔ ( 𝐴 + 𝐶 ) = 𝐶 ) ) |
17 |
13 16
|
mpbid |
⊢ ( ( 𝜑 ∧ 𝐶 ∈ ℝ ) → ( 𝐴 + 𝐶 ) = 𝐶 ) |