package require Tcl 8.6
proc abc {word {blocks {BO XK DQ CP NA GT RE TG QD FS JW HU VI AN OB ER FS LY PC ZM}}} {
set abc {{letters blocks abc} {
set rest [lassign $letters ch]
set i 0
foreach blk $blocks {
if {$ch in $blk && (![llength $rest]
|| [apply $abc $rest [lreplace $blocks $i $i] $abc])} {
return true
}
incr i
}
return false
}}
return [apply $abc [split $word ""] [lmap b $blocks {split $b ""}] $abc]
}
foreach word {"" A BARK BOOK TREAT COMMON SQUAD CONFUSE} {
puts [format "Can we spell %9s? %s" '$word' [abc $word]]
}