This is METAFONT, WAITS Version 0.76 (preloaded base=plain 85.2.2)  7 FEB 1985 17:35
**\tracingall

*input 6test
{input}
(6TEST.MF[CM,DEK]
{input}
(CMBASE.MF[CM,DEK]
{cmbase:=1}
## cmbase=1
{if}
{known(1)}
{true}

font_family<expr>->headerbyte49:BCPL_string((EXPR0),20);special"fontfamily "&(E
XPR0)
(EXPR0)<-fontidentifier
{headerbyte}

BCPL_string(EXPR0)(EXPR1)->for.l:=if.length((EXPR0))>=(EXPR1):(EXPR1)-1else:len
gth((EXPR0))fi:l.for.k:=1upto.l:,substring(k-1,k)of(EXPR0)endfor.for.k:=l+2upto
(EXPR1):,0endfor.endfor
(EXPR0)<-fontidentifier
(EXPR1)<-20
{for}
{if}
{length(fontidentifier)}
>> fontidentifier
! Not implemented: length(unknown numeric).
<to be read again> 
                   >=
BCPL_string->for.l:=if.length((EXPR0))>=
                                        (EXPR1):(EXPR1)-1else:length(...
font_family->...49:BCPL_string((EXPR0),20)
                                          ;special"fontfamily "&(EXPR0)
<to be read again> 
                   ;
p.2,l.4 ...ld: font_family fontidentifier;
                                           fi
? e
 
Here is how much of METAFONT's memory you used:
 5 strings out of 301
 52 string characters out of 10323
 4582 words of memory out of 60001
 466 symbolic tokens out of 2100
 5i,50n,0r,3p,119b stack positions out of 30i,100n,100r,150p,500b