restricted system commands enabled.
(./input-level-string.tex
[1]\a ->\b \relax
[2]\b #1->\c \relax
[2]#1<-\relax
[2]\c ->\d \relax
[3]\d ->x
[1]\a ->\b \relax
[2]\b #1->\c \relax
[2]#1<-\relax
[2]\c ->\d \relax
[3]\d ->x
{horizontal mode: the letter x}
{\relax}
{\relax}
{the letter y}
{blank space }
{\tracingcommands}
[1]\a ->\b \relax
[2]\b #1->\c \relax
[2]#1<-\relax
[2]\c ->\d \relax
[3]\d ->x
### horizontal mode entered at line 14
\localpar
.\localinterlinepenalty=0
.\localbrokenpenalty=0
.\localleftbox=null
.\localrightbox=null
\hbox(0.0+0.0)x0.0, direction TLT
\nullfont x
\nullfont y
\glue(\spaceskip) 0.0
etc.
spacefactor 1000
### vertical mode entered at line 0
prevdepth ignored
! OK.
l.19 \showlists
[0])
(see the transcript file for additional information)
Output written on input-level-string.dvi (1 page, 132 bytes).
Transcript written on input-level-string.log.