definition dfr (p) (q): relation2 prototerm prototerm ≝
λt1,t2. ∃n:pnat.
let r ≝ p●𝗔◗𝗟◗q in
- ∧∧ (𝗟◗q)ᴿ = ↳[n](rᴿ) & r◖𝗱n ϵ t1 &
- t1[â\8b\94râ\86\90ð\9d\9b\97n.(t1⋔(p◖𝗦))] ⇔ t2
+ ∧∧ (𝗟◗q)ᴿ = ↳[n](𝗟◗q)ᴿ & r◖𝗱n ϵ t1 &
+ t1[â\8b\94râ\86\90ð\9d\9b\95n.(t1⋔(p◖𝗦))] ⇔ t2
.
interpretation