infer nifer ifner finer nfier fnier inefr niefr ienfr einfr neifr enifr ifenr fienr iefnr eifnr feinr efinr nfeir fneir nefir enfir fenir efnir infre nifre ifnre finre nfire fnire inrfe nirfe irnfe rinfe nrife rnife ifrne firne irfne rifne frine rfine nfrie fnrie nrfie rnfie frnie rfnie inerf nierf ienrf einrf neirf enirf inref niref irnef rinef nrief rnief iernf eirnf irenf rienf erinf reinf nerif enrif nreif rneif ernif renif ifern fiern iefrn eifrn feirn efirn ifren firen irfen rifen frien rfien ierfn eirfn irefn riefn erifn reifn ferin efrin frein rfein erfin refin nferi fneri nefri enfri fenri efnri nfrei fnrei nrfei rnfei frnei rfnei nerfi enrfi nrefi rnefi ernfi renfi ferni efrni freni rfeni erfni refni
Note: these 'words' (valid or invalid) are all the permutations of the word infer. These words are obtained by scrambling the letters in infer.