COMMENT ⊗ VALID 00002 PAGES C REC PAGE DESCRIPTION C00001 00001 C00002 00002 \input basic C00003 ENDMK C⊗; \input basic \trace'77777777 \def\array#1\\#2\endarray{\xdef\ident{#1} \vcenter{\halign{\tabskip0pt\ident\ddt\cr#2\cr}}} \def\c{\hfill$##$\hfill} \def\\{\cr} $\array\c\ddt\quad⊗\c\\ a⊗b\\ c⊗d\endarray$