eqn

Process equations in troff input

$ eqn [document.ms] | troff -ms

$ groff -e -ms [document.ms]

$ eqn [equations.eqn]

eqn [options] [files...]

eqn is a preprocessor for troff that formats mathematical equations. It converts a high-level equation description language into troff commands for typeset output.
Equations are enclosed between .EQ and .EN macros or inline delimiters. The language uses words like "over" for fractions, "sup" for superscripts, and "sqrt" for roots.
eqn is typically used in a pipeline with troff/groff for producing technical documents with mathematical notation.

FILES

Input files containing equations.

Set delimiters for inline equations.

Set font for equations.

Set point size.

Subscript/superscript size reduction.

Recognize .EQ and .EN even in comments.

Syntax differs from LaTeX. Output requires troff processing. Complex equations need careful formatting. Limited symbol set compared to TeX.

eqn was written by Brian Kernighan and Lorinda Cherry at Bell Labs in the 1970s. It was one of the first tools for typesetting mathematics and influenced later systems.

groff(1), troff(1), tbl(1), pic(1)