| # ax = # kx ⊦ new(ax, fs) ∧ kx.toSet ⊆ dom ri ∧ ¬ dups(kx) ∧ ¬ dups(ax) ∧ ri-cons(ri, fs) → abs-dirs(fs[ax, fs[ri[kx]]], ri[kx, ax]) = abs-dirs(fs, ri) |
# ax = # kx, new(ax, fs), ri-cons(ri, fs), kx.toSet ⊆ dom ri ⊦ abs-dirs(fs[ax, fs[ri[kx]]], ri[kx, ax]) = abs-dirs(fs, ri), dups(ax), dups(kx)