nabla anbla nbala bnala abnla banla nalba anlba nlaba lnaba alnba lanba nblaa bnlaa nlbaa lnbaa blnaa lbnaa ablna balna albna labna blana lbana nabal anbal nbaal bnaal abnal banal naabl anabl naabl anabl aanbl aanbl nbaal bnaal nabal anbal banal abnal abanl baanl aabnl aabnl baanl abanl nalab anlab nlaab lnaab alnab lanab naalb analb naalb analb aanlb aanlb nlaab lnaab nalab anlab lanab alnab alanb laanb aalnb aalnb laanb alanb nblaa bnlaa nlbaa lnbaa blnaa lbnaa nbala bnala nabla anbla banla abnla nlaba lnaba nalba anlba lanba alnba blana lbana balna ablna labna albna ablan balan alban laban blaan lbaan abaln baaln aabln aabln baaln abaln alabn laabn aalbn aalbn laabn alabn blaan lbaan balan ablan laban alban
Note: these 'words' (valid or invalid) are all the permutations of the word nabla. These words are obtained by scrambling the letters in nabla.