ROOTS

no extend_word for now, it is in conflict with manual reformatting of sources via TAB (e.g. accidental replacement of 'assume' by 'assumes');

src/Pure
src/FOL
src/HOL
src/ZF
src/CCL
src/CTT
src/Cube
src/FOLP
src/LCF
src/Sequents
src/Doc
src/Tools