| Step | Hyp | Ref | Expression | 
						
							| 1 |  | zrhpsgnelbas.p | ⊢ 𝑃  =  ( Base ‘ ( SymGrp ‘ 𝑁 ) ) | 
						
							| 2 |  | zrhpsgnelbas.s | ⊢ 𝑆  =  ( pmSgn ‘ 𝑁 ) | 
						
							| 3 |  | zrhpsgnelbas.y | ⊢ 𝑌  =  ( ℤRHom ‘ 𝑅 ) | 
						
							| 4 | 1 2 | psgnran | ⊢ ( ( 𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑆 ‘ 𝑄 )  ∈  { 1 ,  - 1 } ) | 
						
							| 5 | 4 | 3adant1 | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑆 ‘ 𝑄 )  ∈  { 1 ,  - 1 } ) | 
						
							| 6 |  | elpri | ⊢ ( ( 𝑆 ‘ 𝑄 )  ∈  { 1 ,  - 1 }  →  ( ( 𝑆 ‘ 𝑄 )  =  1  ∨  ( 𝑆 ‘ 𝑄 )  =  - 1 ) ) | 
						
							| 7 |  | eqid | ⊢ ( 1r ‘ 𝑅 )  =  ( 1r ‘ 𝑅 ) | 
						
							| 8 | 3 7 | zrh1 | ⊢ ( 𝑅  ∈  Ring  →  ( 𝑌 ‘ 1 )  =  ( 1r ‘ 𝑅 ) ) | 
						
							| 9 |  | eqid | ⊢ ( Base ‘ 𝑅 )  =  ( Base ‘ 𝑅 ) | 
						
							| 10 | 9 7 | ringidcl | ⊢ ( 𝑅  ∈  Ring  →  ( 1r ‘ 𝑅 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 11 | 8 10 | eqeltrd | ⊢ ( 𝑅  ∈  Ring  →  ( 𝑌 ‘ 1 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 12 | 11 | 3ad2ant1 | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ 1 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 13 |  | fveq2 | ⊢ ( ( 𝑆 ‘ 𝑄 )  =  1  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  =  ( 𝑌 ‘ 1 ) ) | 
						
							| 14 | 13 | eleq1d | ⊢ ( ( 𝑆 ‘ 𝑄 )  =  1  →  ( ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 )  ↔  ( 𝑌 ‘ 1 )  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 15 | 12 14 | imbitrrid | ⊢ ( ( 𝑆 ‘ 𝑄 )  =  1  →  ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 16 |  | neg1z | ⊢ - 1  ∈  ℤ | 
						
							| 17 |  | eqid | ⊢ ( .g ‘ 𝑅 )  =  ( .g ‘ 𝑅 ) | 
						
							| 18 | 3 17 7 | zrhmulg | ⊢ ( ( 𝑅  ∈  Ring  ∧  - 1  ∈  ℤ )  →  ( 𝑌 ‘ - 1 )  =  ( - 1 ( .g ‘ 𝑅 ) ( 1r ‘ 𝑅 ) ) ) | 
						
							| 19 | 16 18 | mpan2 | ⊢ ( 𝑅  ∈  Ring  →  ( 𝑌 ‘ - 1 )  =  ( - 1 ( .g ‘ 𝑅 ) ( 1r ‘ 𝑅 ) ) ) | 
						
							| 20 |  | ringgrp | ⊢ ( 𝑅  ∈  Ring  →  𝑅  ∈  Grp ) | 
						
							| 21 | 16 | a1i | ⊢ ( 𝑅  ∈  Ring  →  - 1  ∈  ℤ ) | 
						
							| 22 | 9 17 20 21 10 | mulgcld | ⊢ ( 𝑅  ∈  Ring  →  ( - 1 ( .g ‘ 𝑅 ) ( 1r ‘ 𝑅 ) )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 23 | 19 22 | eqeltrd | ⊢ ( 𝑅  ∈  Ring  →  ( 𝑌 ‘ - 1 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 24 | 23 | 3ad2ant1 | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ - 1 )  ∈  ( Base ‘ 𝑅 ) ) | 
						
							| 25 |  | fveq2 | ⊢ ( ( 𝑆 ‘ 𝑄 )  =  - 1  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  =  ( 𝑌 ‘ - 1 ) ) | 
						
							| 26 | 25 | eleq1d | ⊢ ( ( 𝑆 ‘ 𝑄 )  =  - 1  →  ( ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 )  ↔  ( 𝑌 ‘ - 1 )  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 27 | 24 26 | imbitrrid | ⊢ ( ( 𝑆 ‘ 𝑄 )  =  - 1  →  ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 28 | 15 27 | jaoi | ⊢ ( ( ( 𝑆 ‘ 𝑄 )  =  1  ∨  ( 𝑆 ‘ 𝑄 )  =  - 1 )  →  ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 29 | 6 28 | syl | ⊢ ( ( 𝑆 ‘ 𝑄 )  ∈  { 1 ,  - 1 }  →  ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 ) ) ) | 
						
							| 30 | 5 29 | mpcom | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝑁  ∈  Fin  ∧  𝑄  ∈  𝑃 )  →  ( 𝑌 ‘ ( 𝑆 ‘ 𝑄 ) )  ∈  ( Base ‘ 𝑅 ) ) |