COMMENT ⊗   VALID 00002 PAGES
C REC  PAGE   DESCRIPTION
C00001 00001
C00002 00002	.<< LENGTHWISE ENVELOPE
C00004 ENDMK
C⊗;
.<< LENGTHWISE ENVELOPE;
.font A "fixr16"; select A;
.turn on "≡" for "#";
.turn on "\";
.macro rot(top,width,εsss);	⊂
.  macro inner;	⊂
.    while(|c>0|,|yyy←yyy&xxx[c]; c←c-width;|);
.    ⊃
.  macro linout;	⊂ yyy}
.    ⊃
.xxx←"";  yyy←"sss";  n←0;
.while("length(yyy)>0",|  zzz←scan(yyy,"↓","","IS");  foo←scan(zzz," ","","XR");
.  if length(zzz)≥width then xxx←xxx&zzz[1 to width] else
.	xxx←xxx&zzz&blanks[1 to width-length(zzz)];|);
.tabs (top-length(xxx)/width+1);  n←length(xxx)-width+1;
.while(|n≤length(xxx)|,|c←n; yyy←"\"; inner; linout; n←n+1;|);
.⊃
.macro ENVEL(who);	⊂
.next page; group skip;
.rot(80,40,fro);
.tostr←via&"↓↓↓↓"&"who";
.rot(72,45,tostr);
.⊃
.blanks←"≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡≡";
.>>