: new-child ( new-child node -- node' expansion/f )
dup full? [ tuck level>> 1node ] [ node-add f ] if ;
: new-last ( val seq -- seq' )
: new-child ( new-child node -- node' expansion/f )
dup full? [ tuck level>> 1node ] [ node-add f ] if ;
: new-last ( val seq -- seq' )