Binary and relational operators

Some "math" symbols are obtained by typing the corresponding keyboard character. Examples include

 + - = < >

Note: plus, minus, and equal sign may be used in either text or math mode, but < and > are math mode only (they produce inverted exclamation and question marks, respectively, in text mode).

The following commands may be used only in math mode.

\pm plus or minus sign
\mp minus or plus sign
\times times (an "x")
\div divided by sign
\ast an asterisk (centered)
\star a five-point star (centered)
\bullet a bullet
\circ an open bullet
\cdot a centered dot (see also, \cdots)
\leq less than or equal to
\ll much less than
\subset is a subset of
\geq greater than or equal to
\gg much greater than
\equiv equivalence symbol
\sim similar to
\simeq similar or equal to
\approx approximately equal to
\neq not equal to
\per "perpendicular to" symbols
\propto proportional to

Note that "greater than" and "less than" are obtained simply by entering > and <.

A slash, indicating "not" can be placed through a symbol (or a letter) with the \not command. For example, not less than is

  \not<

and not less than or equal to is

 \not\leq

If the slash isn't properly positioned it can be moved by putting a math mode spacing command between the \not and the symbol.