var blocks=T("BO", "XK", "DQ", "CP", "NA", "GT", "RE", "TG", "QD", "FS",
	     "JW", "HU", "VI", "AN", "OB", "ER", "FS", "LY", "PC", "ZM", );

fcn can_make_word(word){
   fcn(blks,word){
      if (not word) return(True);  // bottom of recursion
      foreach b in (blks){ n:=__bWalker.idx;
	 if(not b.holds(word[0])) continue; // letter not on this block
	 blks.del(n);		// remove this block from pile
	 if (self.fcn(blks,word[1,*])) return(True);  // try remaining blocks
	 blks.insert(n,b);	// put block back in pile: backtracking
      }
      False;   // out of blocks but not out of word
   }(blocks.copy(),word.toUpper())
}

foreach word in (T("","A","BarK","BOOK","TREAT","COMMON","SQUAD","Confuse","abba")){
   can_make_word(word).println(": ",word);
}