| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cchhl.c | ⊢ 𝐶  =  ( ( ( subringAlg  ‘ ℂfld ) ‘ ℝ )  sSet  〈 ( ·𝑖 ‘ ndx ) ,  ( 𝑥  ∈  ℂ ,  𝑦  ∈  ℂ  ↦  ( 𝑥  ·  ( ∗ ‘ 𝑦 ) ) ) 〉 ) | 
						
							| 2 |  | cchhllem.1 | ⊢ 𝐸  =  Slot  ( 𝐸 ‘ ndx ) | 
						
							| 3 |  | cchhllem.2 | ⊢ ( Scalar ‘ ndx )  ≠  ( 𝐸 ‘ ndx ) | 
						
							| 4 |  | cchhllem.3 | ⊢ (  ·𝑠  ‘ ndx )  ≠  ( 𝐸 ‘ ndx ) | 
						
							| 5 |  | cchhllem.4 | ⊢ ( ·𝑖 ‘ ndx )  ≠  ( 𝐸 ‘ ndx ) | 
						
							| 6 | 5 | necomi | ⊢ ( 𝐸 ‘ ndx )  ≠  ( ·𝑖 ‘ ndx ) | 
						
							| 7 | 2 6 | setsnid | ⊢ ( 𝐸 ‘ ( ( subringAlg  ‘ ℂfld ) ‘ ℝ ) )  =  ( 𝐸 ‘ ( ( ( subringAlg  ‘ ℂfld ) ‘ ℝ )  sSet  〈 ( ·𝑖 ‘ ndx ) ,  ( 𝑥  ∈  ℂ ,  𝑦  ∈  ℂ  ↦  ( 𝑥  ·  ( ∗ ‘ 𝑦 ) ) ) 〉 ) ) | 
						
							| 8 |  | eqidd | ⊢ ( ⊤  →  ( ( subringAlg  ‘ ℂfld ) ‘ ℝ )  =  ( ( subringAlg  ‘ ℂfld ) ‘ ℝ ) ) | 
						
							| 9 |  | ax-resscn | ⊢ ℝ  ⊆  ℂ | 
						
							| 10 |  | cnfldbas | ⊢ ℂ  =  ( Base ‘ ℂfld ) | 
						
							| 11 | 9 10 | sseqtri | ⊢ ℝ  ⊆  ( Base ‘ ℂfld ) | 
						
							| 12 | 11 | a1i | ⊢ ( ⊤  →  ℝ  ⊆  ( Base ‘ ℂfld ) ) | 
						
							| 13 | 8 12 2 3 4 5 | sralem | ⊢ ( ⊤  →  ( 𝐸 ‘ ℂfld )  =  ( 𝐸 ‘ ( ( subringAlg  ‘ ℂfld ) ‘ ℝ ) ) ) | 
						
							| 14 | 13 | mptru | ⊢ ( 𝐸 ‘ ℂfld )  =  ( 𝐸 ‘ ( ( subringAlg  ‘ ℂfld ) ‘ ℝ ) ) | 
						
							| 15 | 1 | fveq2i | ⊢ ( 𝐸 ‘ 𝐶 )  =  ( 𝐸 ‘ ( ( ( subringAlg  ‘ ℂfld ) ‘ ℝ )  sSet  〈 ( ·𝑖 ‘ ndx ) ,  ( 𝑥  ∈  ℂ ,  𝑦  ∈  ℂ  ↦  ( 𝑥  ·  ( ∗ ‘ 𝑦 ) ) ) 〉 ) ) | 
						
							| 16 | 7 14 15 | 3eqtr4i | ⊢ ( 𝐸 ‘ ℂfld )  =  ( 𝐸 ‘ 𝐶 ) |