sthal tshal shtal hstal thsal htsal stahl tsahl sathl asthl tashl atshl shatl hsatl sahtl ashtl hastl ahstl thasl htasl tahsl athsl hatsl ahtsl sthla tshla shtla hstla thsla htsla stlha tslha sltha lstha tlsha ltsha shlta hslta slhta lshta hlsta lhsta thlsa htlsa tlhsa lthsa hltsa lhtsa stalh tsalh satlh astlh taslh atslh stlah tslah sltah lstah tlsah ltsah salth aslth slath lsath alsth lasth talsh atlsh tlash ltash altsh latsh shalt hsalt sahlt ashlt haslt ahslt shlat hslat slhat lshat hlsat lhsat salht aslht slaht lsaht alsht lasht halst ahlst hlast lhast alhst lahst thals htals tahls athls hatls ahtls thlas htlas tlhas lthas hltas lhtas talhs atlhs tlahs ltahs alths laths halts ahlts hlats lhats alhts lahts
Note: these 'words' (valid or invalid) are all the permutations of the word sthal. These words are obtained by scrambling the letters in sthal.