trefa rtefa terfa etrfa retfa ertfa trfea rtfea tfrea ftrea rftea frtea tefra etfra tfera ftera eftra fetra refta erfta rfeta freta efrta ferta treaf rteaf teraf etraf retaf ertaf traef rtaef taref atref ratef artef tearf etarf taerf aterf eatrf aetrf reatf eratf raetf aretf eartf aertf trfae rtfae tfrae ftrae rftae frtae trafe rtafe tarfe atrfe ratfe artfe tfare ftare tafre atfre fatre aftre rfate frate rafte arfte farte afrte tefar etfar tfear ftear eftar fetar teafr etafr taefr atefr eatfr aetfr tfaer ftaer tafer atfer fater after efatr featr eaftr aeftr faetr afetr refat erfat rfeat freat efrat ferat reaft eraft raeft areft earft aerft rfaet fraet rafet arfet faret afret efart feart eafrt aefrt faert afert
Note: these 'words' (valid or invalid) are all the permutations of the word trefa. These words are obtained by scrambling the letters in trefa.