BODY=intro lang line comm post obs

out   :
      eqn  header $(BODY) | troff -ms >out

try   :
      neqn  header $(BODY) | nroff -ms >out
zap% make
## working directory is /u2/docsourc/doc/Jwork/ideal/refman ###################
eqn  header intro lang line comm post obs | troff -ms >out
troff: Can't open /usr/lib/font/dev480/PA.out
troff: Can't open /usr/lib/font/dev480/PI.out
troff: Can't open /usr/lib/font/dev480/PB.out
troff: Can't open /usr/lib/font/dev480/SP.out
troff: Can't open /usr/lib/font/dev480/SI.out
troff: can't open file /usr/bwk/src/cprog.mac

*** Exit 141

Stop.
zap%