.SC "A Large Example".PPHere is the complete source for the three display equationsin the abstract of this guide..sp.nf.ps -2.vs -2 .EQ I G(z)~mark =~ e sup { ln ~ G(z) } ~=~ exp left (  sum from k>=1 {S sub k z sup k} over k right ) ~=~  prod from k>=1 e sup {S sub k z sup k /k} .EN .EQ I lineup = left ( 1 + S sub 1 z +  { S sub 1 sup 2 z sup 2 } over 2! + ... right ) left ( 1+ { S sub 2 z sup 2 } over 2 + { S sub 2 sup 2 z sup 4 } over { 2 sup 2 cdot 2! } + ... right ) ... .EN .EQ I lineup =  sum from m>=0 left ( sum from pile { k sub 1 ,k sub 2 ,..., k sub m  >=0 above k sub 1 +2k sub 2 + ... +mk sub m =m} { S sub 1 sup {k sub 1} } over {1 sup k sub 1 k sub 1 ! } ~ { S sub 2 sup {k sub 2} } over {2 sup k sub 2 k sub 2 ! } ~ ... { S sub m sup {k sub m} } over {m sup k sub m k sub m ! }  right ) z sup m .EN.sp.fi.ps +2.vs +2.SC "Keywords, Precedences, Etc.".PPIf you don't use braces,.UC EQNwilldo operations in the order shown in this list..P1 3.ft Idyad vec under bar tilde hat dot dotdotfwd  back  down  upfat  roman  italic  bold  sizesub  sup  sqrt  overfrom  to.ft R.P2These operations group to the left:.P1.ft Iover  sqrt  left  right.ft R.P2All others group to the right..PPDigits, parentheses, brackets, punctuation marks, and these mathematical wordsare convertedto Roman font when encountered:.P1sin  cos  tan  sinh  cosh  tanh  arcmax  min  lim  log  ln  expRe  Im  and  if  for  det.P2These character sequences are recognized and translated as shown..sp.nf.tr -\(mi.in .5i.ta 1i>=		$>=$<=		$<=$==		$==$!=		$!=$+-		$+-$->		$->$<-		$<-$<<		$<<$>>		$>>$inf		$inf$partial		$partial$half		$half$prime		$prime$approx		$approx$nothing		$nothing$cdot		$cdot$times		$times$del		$del$grad		$grad$\&...		$...$,...,		$,...,$sum		$sum$.sp 3pint		$int$.sp 2pprod		$prod$union		$union$inter		$inter$.sp.in.fi.tr --.PPTo obtain Greek letters,simply spell them out in whatever case you want:.sp.nf.in .2i.ta .7i 1.4i 2.1iDELTA	$DELTA$	iota	$iota$GAMMA	$GAMMA$	kappa	$kappa$LAMBDA	$LAMBDA$	lambda	$lambda$OMEGA	$OMEGA$	mu	$mu$PHI	$PHI$	nu	$nu$PI	$PI$	omega	$omega$PSI	$PSI$	omicron	$omicron$SIGMA	$SIGMA$	phi	$phi$THETA	$THETA$	pi	$pi$UPSILON	$UPSILON$	psi	$psi$XI	$XI$	rho	$rho$alpha	$alpha$	sigma	$sigma$beta	$beta$	tau	$tau$chi	$chi$	theta	$theta$delta	$delta$	upsilon	$upsilon$epsilon	$epsilon$	xi	$xi$eta	$eta$	zeta	$zeta$gamma	$gamma$.sp.in.fi.PPThese are all the words known to.UC EQN(except for characters with names),together with the section where they are discussed..sp.nf.in .2i.ta .7i 1.4i 2.1iabove	17, 18	lpile	17back	21	mark	15bar	13	matrix	18bold	12	ndefine	20ccol	18	over	9col	18	pile	17cpile	17	rcol	18define	20	right	16delim	19	roman	12dot	13	rpile	17dotdot	13	size	12down	21	sqrt	10dyad	13	sub	7fat	12	sup	7font	12	tdefine	20from	11	tilde	13fwd	21	to	11gfont	12	under	13gsize	12	up	21hat	13	vec	13italic	12	~, ^	4, 6lcol	18	{ }	8left	16	"..."	8, 14lineup	15.sp.in 0.fi.SC Troubleshooting.PPIf you make a mistake in an equation,like leaving out a brace (very common)or having one too many (very common)or having a.ulsupwith nothing before it (common),.UC EQNwill tell you with the message.P1 2.ft Isyntax error between lines x and y, file z.ft R.P2where.ulxand.ulyare approximately the linesbetween which the trouble occurred, and.ulzis the nameof the file in question.The line numbers are approximate _ look nearby as well.There are also self-explanatory messages that arise if you leave out a quoteor try to run.UC EQNon a non-existent file..PPIf you want to check a document before actually printing it(on.UC UNIX only),.P1eqn  files >/dev/null.P2willthrow away the output but print the messages..PPIf you use something like dollar signs as delimiters,it is easy to leave one out.This causes very strange troubles.The program.ulcheckeq(on.UC GCOS ,use.ul\&./checkeqinstead)checks for misplaced or missing dollar signsand similar troubles..PPIn-line equations can only be so bigbecause of an internal buffer in.UC TROFF .If you get a message``word overflow'',you have exceeded this limit.If you print the equation as a displayed equationthis message will usually go away.The message``line overflow''indicates you have exceeded an even bigger buffer.The only cure for this is to break the equation into two separate ones..PPOn a related topic,.UC EQNdoes not break equations by itself _you must split long equations up across multiple linesby yourself,marking each by a separate.UC .EQ\&...\&.UC .ENsequence..UC EQNdoes warn about equations that are too longto fit on one line.