Naming the diagram arrows.

The rules for naming the diagram arrows are analogous to those for naming the in-text arrows, with the additional possibility of naming the arrow on either of its sides. It suffice to type the first or the last letter of the command as an upper-case letter and give the name of the arrow as an argument. Here is an exhaustive list of the available possibilities.

Eql:
An equality cannot be named
Vertical ar, mono, epi, bimo:
A first upper-case letter produces a left name and a last upper-case letter produces a right name; thus type +f+ to draw a south monomorphism with left name f and +g+ to draw a north epimorphism with right name g.
Non-vertical ar, mono, epi, bimo:
A first upper-case letter produces an upper name and a last upper-case letter produces a lower name; thus type +f+ to draw a west arrow with upper name f and +g+ to draw a north-east bimorphism with lower name g.
Horizontal iso:
A first upper-case letter produces an upper name and a last upper-case letter produces a lower name; thus type +f+ to draw a west isomorphism with upper name f and +g+ to draw an east isomorphism with lower name g.
Non-horizontal iso:
Type a first upper-case letter to name it; the name will appear on one side of the arrow and the ``isomorphism symbol'' on the other side; thus +f+ draws a north-west isomorphism with name f.
Vertical biar, adjar:
Type a first upper-case letter to name them and give successively the name of the left arrow and that of the right arrow; thus +fg+ draws a pair of south arrows with left name f and right name g.
Non-vertical biar, adjar:
Type a first upper-case letter to name them and give successively the name of the upper arrow and that of the lower arrow; thus +fg+ will produce a south-east pair of adjoint arrows with upper name f and lower name g.

The name of an arrow will always be processed in Math mode at the textstyle size; therefore the text characters will be printed in Math italic and you should not type any $ sign to introduce a mathematical symbol in the name of an arrow. The name of an arrow will automatically be positioned in order not to bump into the corresponding arrow.