ring homomorphism math eta colon r math whose image lies center ''a'' make ''a'' ''r'' algebra defining math r cdot x eta r x math ''r'' ''r'' ''x'' ''a'' ''a'' ''r'' algebra taking ''x'' formula turn defines ring homomorphism math eta colon r math whose image lies center ring commutative equals center commutative ''r'' algebra defined simply commutative ring ''a'' together commutative ring homomorphism math eta colon r math
Formal science Mathematics Pure mathematics Algebra Associative algebra