Weak Pullbacks
A weak pullback of a cospan X → Z ← Y is a cone over the cospan that is only weakly universal, that is, the mediating morphism u : Q → P above need not be unique.
Read more about this topic: Pullback (category Theory)
Famous quotes containing the word weak:
“Public opinion is a weak tyrant compared with our own private opinion. What a man thinks of himself, that it is which determines, or rather indicates, his fate.”
—Henry David Thoreau (1817–1862)