- let rec ctrans (hds: PList) on hds: (nat \to (T \to T)) \def (\lambda (i:
-nat).(\lambda (t: T).(match hds with [PNil \Rightarrow t | (PCons h d hds0)
-\Rightarrow (let j \def (trans hds0 i) in (let u \def (ctrans hds0 i t) in
-(match (blt j d) with [true \Rightarrow (lift h (minus d (S j)) u) | false
-\Rightarrow u])))]))) in ctrans.
+ let rec ptrans (hds: PList) on hds: (nat \to PList) \def (\lambda (i:
+nat).(match hds with [PNil \Rightarrow PNil | (PCons h d hds0) \Rightarrow
+(let j \def (trans hds0 i) in (let q \def (ptrans hds0 i) in (match (blt j d)
+with [true \Rightarrow (PCons h (minus d (S j)) q) | false \Rightarrow
+q])))])) in ptrans.