Introduction to Category Theory/Equalizers

Example

$f(x,y)=x^{2}+y^{2},g(x,y)=1\;$

Equalizer is $\{(x,y)\in \mathbb {R} ^{2}\;|\;x^{2}+y^{2}=1\}$ plus projection map.

Related Resources

• w:Equaliser (mathematics)
• w:Coequalizer