16.2 EqnEqn is a preprocessor designed to facilitate the typesetting of mathematical equations. Use neqn with nroff. Eqn has the following commandline syntax:
16.2.1 Eqn Macros
Use the 16.2.2 Mathematical CharactersThe character sequences below are recognized and translated as shown:
16.2.3 Mathematical TextDigits, parentheses, brackets, punctuation marks, and the following mathematical words are printed out in Roman font:
sin cos tan arc sinh cosh tanh and if for det max min lim log ln exp Re Im 16.2.4 Greek CharactersGreek letters can be printed in uppercase or lowercase. To obtain Greek letters, simply spell them out. Some uppercase Greek letters are not supported because they can be specified by an Arabic equivalent (e.g, A for alpha, B for beta).
16.2.5 Diacritical Marks
Several keywords are available to mark the tops of characters.
Eqn centers a mark at the correct height.
16.2.6 Keywords Recognized by EqnIn addition to character names and diacritical marks, eqn recognizes the following keywords:
16.2.7 PrecedenceIf you don't use braces, eqn will do operations in the order shown in this list, reading from left to right.
These operations group to the left:
over sqrt left right All others group to the right. 16.2.8 Eqn ExamplesInput:
.EQ delim %% .EN %sum from i=0 to inf c sup i~=~lim from {m > inf} sum from i=0 to m c sup i% .EQ delim off .EN Result: Input:
.EQ delim %% .EN %x ~=~ left [ { b ~+~ sqrt {b sup 2  ~4ac} } over 2a right ]% .EQ delim off .EN  
