` ` ` ` ` `EQN
knows some mathematical symbols,
some mathematical names, and the Greek alphabet.` `
For example,
x=2 pi int sin ( omega t)dt

produces

Here the spaces in the input are
**
necessary
**
to tell
EQN
that
int,
pi,
sin
and
omega
are separate entities that should get special treatment.` `
The
sin,
digit 2, and parentheses are set in roman type instead of italic;
pi
and
omega
are made Greek;
and
int
becomes the integral sign.` `

` ` ` ` ` `When in doubt, leave spaces around separate parts of the input.` `
A
very
common error is to type
f(pi)
without leaving spaces on both sides of the
pi.` `
As a result,
EQN
does not recognize
pi
as a special word, and it appears as
instead of
.` `

` ` ` ` ` `A complete list of
EQN
names appears in section 23.` `
Knowledgeable users can also use
TROFF
four-character names
for anything
EQN
doesn't know about,
like
\(bs
for the Bell System sign \(bs.` `