In such cases, role spans stay limited to the preposition and is not expanded to the PP:
%%% This output was generated by the following command:
%%% bin/boxer --input out/p00/d0852/en.parse.tags --semantics drg --resolve --tense --instantiate --modal --theory sdrt --copula false --nn --elimeq --roles verbnet --integrate --warnings false --output out/p00/d0852/en.drs.clf
%%% ø Oil has been discovered under the North~Sea .
b1 REF x1 % Oil [0...3]
b1 oil "n.03" x1 % Oil [0...3]
% has [4...7]
b1 REF t1 % been [8...12]
b1 TPR t1 "now" % been [8...12]
b1 Time e1 t1 % been [8...12]
b1 time "n.08" t1 % been [8...12]
b1 REF e1 % discovered [13...23]
b1 Theme e1 x1 % discovered [13...23]
b1 discover "v.03" e1 % discovered [13...23]
b1 REF x3 % under [24...29]
b1 Location e1 x3 % under [24...29]
b1 SZP x2 x3 % under [24...29]
b1 location "n.01" x3 % under [24...29]
b2 REF x2 % the [30...33]
b2 PRESUPPOSITION b1 % the [30...33]
b2 Name x2 "north~sea" % North~Sea [34...43]
b2 sea "n.01" x2 % North~Sea [34...43]
% . [43...44]
1 Oil CON oil 4 n rp(s:dcl, ba(s:dcl, lx(np, n, * ) oil.n.03 Theme
2 has NOW have 4 (s:dcl\np)/(s:pt\np) ba(s:dcl\np, fa(s:dcl\np, * O O
3 been PFT be 4 (s:pt\np)/(s:pss\np) fa(s:pt\np, * O O
4 discovered EXS discover 0 s:pss\np * )) discover.v.03 V
5 under REL under 7 ((s\np)\(s\np))/np fa((s\np)\(s\np), * O Location
6 the DEF the 7 np/n fa(np, * O O
7 North~Sea GEO north~sea 4 n * )))) sea.n.01 O
8 . NIL . 4 . * )) O O
In such cases, role spans stay limited to the preposition and is not expanded to the PP: