notes-math-cs353

chapter 4, category theory, page 50, section 4.1.4 constructs specific to graphs, paragraph defining 'initial', potential error: shouldn't it be

cs353 notes, p. 52: why do we need to postulate all those 0 x n and n x 0 matrices in order to make matrices a category? dont't we just need an identity on 0?

p.53 4.1.8 last para "if for all x,y F-xy is injective then F is said to "for all x,y in the target"? consider an inclusion functor

p.54 3rd para: recall that notation C(x,y) means the homset of C from x to y. C(f,z) however is being defined here.

p. 57 section 4.2.2: "has two associated projections functions that we can diagram as the 2-cone": i assume 'we can diagram as the 2-cone' means 'there exists a diagram from the 2-cone to this graph?

p. 57 section 4.2.2: missed parens in the paragraph starting 'A cone'

p. 57 section 4.2.2, diagram on bottom: the subscript 1 in the label of the edge on the left side (the label is supposed to be p_1) is right over the line and so is unreadable