Revert "symmetry of tangle relations"

This reverts commit a1d1b2379502dbad3bd8c5b8c19b8f06eb28e649.
just for gits sake
just for gits sake
Updating
Merge branch 'master' of https://github.com/prathamesh-t/Tangle-Isabelle
prathamesh's updates
Merge branch 'master' of https://github.com/prathamesh-t/Tangle-Isabelle
Merge branch 'master' of https://github.com/prathamesh-t/Tangle-Isabelle
Prathamesh's update
Merge branch 'master' of https://github.com/prathamesh-t/Tangle-Isabelle
debug changes
Merge branch 'master' of https://github.com/prathamesh-t/Tangle-Isabelle
Proper versions
bricklength removed