RPX
From Icelandic Parsed Historical Corpus (IcePaHC)
( (IP-MAT (IP-MAT-1 (HVDI hafði-hafa) (NP-SBJ (NPR-N Egill-egill)) (ADVP-TMP (ADV þá-þá)) (NP-OB1 (ONE-A eitt-einn) (N-N (N21-N lang-langur) (N22-A skip-skip)) (ADJ-A mikið-mikill))) (, .-.) (CONJP (CONJ og-og) (IP-MAT=1 (RPX á-á) (NP-OB1 (NP (NUM-A hundrað-hundrað) (N-A mann-maður)) (CONJP (CONJ eða-eða) (ADVP (ADV vel-vel) (ADVR svo-svo)))) (. .-.)))) (ID THETUBROT,.6))
Sometimes used for possible gapping structures that are PP-internal, as in the RPX conjoined with a PP below:
(PP (PP (P af-af) (NP (N-D sloti-slot))) (CONJP (CONJ eða-eða) (RPX á-á))))