This is METAFONT, Version 2.718 (INIMF)
** &trap  trap 
(trap.mf
\*//*\trap\pass2!
! Missing symbolic token inserted.
<inserted text> 
                 INACCESSIBLE
l.21 ...t next=\; delimiters ^~7
                                ! fi
! Extra tokens will be flushed.
<to be read again> 
                   !
l.21 ... next=\; delimiters ^~7!
                                 fi
! Forbidden token found while scanning to the end of the statement.
<inserted text> 
                ;
<to be read again> 
                   \
l.22 next\
          ; % the second pass will now compute silently; the ...

hello again^^_
>> pen (see the transcript file)
>> path (see the transcript file)
>> path (see the transcript file)
>> path (see the transcript file)
f<expr>->let)=];let[=(;show._
(EXPR0)<-xx
{let}
{let}
{show}
>> _1
{showdependencies}
xpart '=-ypart '-0.66667
{qq:=pen}
{showstats}
Memory usage 1476&588 (104 still untouched)
String usage 39&162 (821&7732 still untouched)
{[repeat the loop]}
! A group begun on line 163 never ended.
<to be read again> 
                   endtext
l.163 ... showstats; bye endtext
                                
{endgroup}
 )
(end occurred when else on line 93 was incomplete)
(end occurred when if on line 36 was incomplete)
(end occurred when elseif on line 21 was incomplete)
(see the transcript file for additional information)
(illegal design size has been changed to 128pt)
(some chardp values had to be adjusted by as much as 0.5pt)
(local label 0:: was missing)
(local label 5:: was missing)
(4 font metric dimensions had to be decreased)
Font metrics written on trap.tfm.
Output written on trap.72270gf (5 characters, 1028 bytes).
Transcript written on trap.log.