brast rbast barst abrst rabst arbst brsat rbsat bsrat sbrat rsbat srbat basrt absrt bsart sbart asbrt sabrt rasbt arsbt rsabt srabt asrbt sarbt brats rbats barts abrts rabts arbts brtas rbtas btras tbras rtbas trbas batrs abtrs btars tbars atbrs tabrs ratbs artbs rtabs trabs atrbs tarbs brsta rbsta bsrta sbrta rsbta srbta brtsa rbtsa btrsa tbrsa rtbsa trbsa bstra sbtra btsra tbsra stbra tsbra rstba srtba rtsba trsba strba tsrba bastr abstr bsatr sbatr asbtr sabtr batsr abtsr btasr tbasr atbsr tabsr bstar sbtar btsar tbsar stbar tsbar astbr satbr atsbr tasbr stabr tsabr rastb arstb rsatb sratb asrtb sartb ratsb artsb rtasb trasb atrsb tarsb rstab srtab rtsab trsab strab tsrab astrb satrb atsrb tasrb starb tsarb
Note: these 'words' (valid or invalid) are all the permutations of the word brast. These words are obtained by scrambling the letters in brast.