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