2022/day13.golfm4

   1 define(d,defn(define))d(f,$1)d(a)d(s,defn(shift))d(c,`+0ifelse($1,$2,`c(',$1,,
   2 `1a(',$2,,`a(',a$1a$2,,`c(f$1,f$2,(s$1),(s$2),',a$1,,`c($1,($2),',a$2,,
   3 `c(($1),$2,',`+($1<$2)a(')s(s($@)))')eval(translit(_(,1,include(i)),[
   4 ],(,)d(_,`ifelse($3,,`) eval((1$1)*(2',`c($3,$4)*$2_(c($3,2)c($4,2)$1,
   5 -~$2s(s(s(s($@)))))c($3,6)c($4,6)')'))))