\input basic \tracingonline1\tracingcommands2\tracingstats2 \tracingpages1\tracingoutput1\tracinglostchars1 \tracingmacros2\tracingparagraphs1\tracingrestores1 \showboxbreadth9999\showboxdepth9999\errorstopmode \def\~#1{{\accent"7E #1}} \xchar550\hbox to10pt{\xchar`A\~x\~X\~{\xchar'570}\~{\xchar'1130}} \tolerance=10000\discretionary{\xchar`a}{\xchar`b}{\xchar`c}\showlists $$\hbox{\xchar0}$$ \end