| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cntrcmnd.z | ⊢ 𝑍  =  ( 𝑀  ↾s  ( Cntr ‘ 𝑀 ) ) | 
						
							| 2 |  | eqid | ⊢ ( Base ‘ 𝑀 )  =  ( Base ‘ 𝑀 ) | 
						
							| 3 |  | eqid | ⊢ ( Cntz ‘ 𝑀 )  =  ( Cntz ‘ 𝑀 ) | 
						
							| 4 | 2 3 | cntrval | ⊢ ( ( Cntz ‘ 𝑀 ) ‘ ( Base ‘ 𝑀 ) )  =  ( Cntr ‘ 𝑀 ) | 
						
							| 5 |  | ssid | ⊢ ( Base ‘ 𝑀 )  ⊆  ( Base ‘ 𝑀 ) | 
						
							| 6 | 2 3 | cntzsubg | ⊢ ( ( 𝑀  ∈  Grp  ∧  ( Base ‘ 𝑀 )  ⊆  ( Base ‘ 𝑀 ) )  →  ( ( Cntz ‘ 𝑀 ) ‘ ( Base ‘ 𝑀 ) )  ∈  ( SubGrp ‘ 𝑀 ) ) | 
						
							| 7 | 5 6 | mpan2 | ⊢ ( 𝑀  ∈  Grp  →  ( ( Cntz ‘ 𝑀 ) ‘ ( Base ‘ 𝑀 ) )  ∈  ( SubGrp ‘ 𝑀 ) ) | 
						
							| 8 | 4 7 | eqeltrrid | ⊢ ( 𝑀  ∈  Grp  →  ( Cntr ‘ 𝑀 )  ∈  ( SubGrp ‘ 𝑀 ) ) | 
						
							| 9 | 1 | subggrp | ⊢ ( ( Cntr ‘ 𝑀 )  ∈  ( SubGrp ‘ 𝑀 )  →  𝑍  ∈  Grp ) | 
						
							| 10 | 8 9 | syl | ⊢ ( 𝑀  ∈  Grp  →  𝑍  ∈  Grp ) | 
						
							| 11 |  | grpmnd | ⊢ ( 𝑀  ∈  Grp  →  𝑀  ∈  Mnd ) | 
						
							| 12 | 1 | cntrcmnd | ⊢ ( 𝑀  ∈  Mnd  →  𝑍  ∈  CMnd ) | 
						
							| 13 | 11 12 | syl | ⊢ ( 𝑀  ∈  Grp  →  𝑍  ∈  CMnd ) | 
						
							| 14 |  | isabl | ⊢ ( 𝑍  ∈  Abel  ↔  ( 𝑍  ∈  Grp  ∧  𝑍  ∈  CMnd ) ) | 
						
							| 15 | 10 13 14 | sylanbrc | ⊢ ( 𝑀  ∈  Grp  →  𝑍  ∈  Abel ) |