The Chicago Manual of Style (sec. 12.16) suggests medium space (a ¼ em) before and after
- signs for binary operations (i.e., conjunctions);
- symbols of integration, summation, or union; and
- signs for binary relations (i.e., verbs)
except in exponents; also medium space after commas between "coordinate points" or between elements in a list; and "no space after a binary operation or relation sign when it is modifying a symbol (i.e., used as an adjective)".
I don't know whether LaTeX follows these guidelines, but anyway I would like to know the (generally accepted) "right" amount of space in the following situations (that is, do I need to add/remove space, and if so how much?)
- after logarithm:
\log x - before factorial symbol:
y! - in an implicit multiplication:
x y - before and after "for all" symbol:
x > 0 \forall x - between equations separated by a comma:
x = 1, y = 2 - between equations separated by text:
x = 1 \text{ and } y = 2 - after a comma separating elements of a set:
\{0, 1\} - after a comma separating arguments of a function:
f(x, y)