PROLOG programming

The following program says nothing about the form of [u,N] before vowels (or rather before adjectives that begin with vowels). It wrongfully predicts that all the instantiations of this prefix will be allowed there. Edit the following program so that these negative adjectives can be correctly generated as output. Also Explain why the instantiator clause of this grammar is not what should be edited to accomodate for these new adjectives

:- ['entailment.swipl'].

:- ['fullproperties.swipl'].

underenglish([P1,P2,P3,P4],[adjective]):-

phone(P1), not(voi(P1)), not(dnt(P1)), lab(P1), phone(P2), mid(P2), not(bck(P2)), not(ctr(P2)), phone(P3), snt(P3), not(nas(P3)), not(alv(P3)), pal(P3), phone(P4), not(snt(P4)), voi(P4), not(cnt(P4)), alv(P4).

underenglish([P1,P2,P3],[adjective]):-

phone(P1), not(voi(P1)), dnt(P1), lab(P1), phone(P2), mid(P2), not(bck(P2)), not(ctr(P2)), phone(P3), not(nas(P3)), alv(P3), pal(P3).

underenglish([P1,P2,P3,P4,P5,P6,P7],[adjective]):-

phone(P1), not(voi(P1)), cnt(P1), cor(P1), not(sib(P1)), phone(P2), hih(P2), not(bck(P2)), not(tns(P2)), phone(P3), nas(P3), phone(P4), not(voi(P4)), vel(P4), phone(P5), not(cns(P5)), not(str(P5)), phone(P6), not(snt(P6)), voi(P6), not(cnt(P6)), lab(P6), phone(P7), snt(P7), not(nas(P7)), alv(P7), not(pal(P7)).

underenglish([P1,P2,P3,P4,P5,P6],[adjective]):-

phone(P1), not(voi(P1)), not(cnt(P1)), alv(P1), phone(P2), hih(P2), not(bck(P2)), not(tns(P2)), phone(P3), not(voi(P3)), not(dnt(P3)), lab(P3), phone(P4), hih(P4), not(bck(P4)), not(tns(P4)), phone(P5), not(voi(P5)), vel(P5), phone(P6), snt(P6), not(nas(P6)), alv(P6), not(pal(P6)).

underenglish([P1,P2,P3,P4,P5,P6,P7,P8],[adjective]):-

phone(P1), not(nas(P1)), alv(P1), pal(P1), phone(P2), not(bck(P2)), tns(P2), phone(P3), snt(P3), not(nas(P3)), alv(P3), not(pal(P3)), phone(P4), mid(P4), not(bck(P4)), not(ctr(P4)), phone(P5), snt(P5), not(nas(P5)), not(alv(P5)), pal(P5), phone(P6), not(voi(P6)), not(cnt(P6)), alv(P6), phone(P7), hih(P7), not(bck(P7)), not(tns(P7)), phone(P8), not(snt(P8)), voi(P8), not(cnt(P8)), alv(P8).

underenglish([P1,P2,P3,P4,P5,P6],[adjective]):-

phone(P1), not(voi(P1)), not(cnt(P1)), pal(P1), phone(P2), mid(P2), not(bck(P2)), not(ctr(P2)), phone(P3), snt(P3), not(nas(P3)), not(alv(P3)), pal(P3), phone(P4), nas(P4), phone(P5), not(snt(P5)), voi(P5), cnt(P5), pal(P5), phone(P6), not(snt(P6)), voi(P6), not(cnt(P6)), alv(P6).

underenglish([P1,P2,P3,P4],[adjective]):-

phone(P1), not(voi(P1)), vel(P1), phone(P2), snt(P2), not(nas(P2)), alv(P2), not(pal(P2)), phone(P3), not(bck(P3)), tns(P3), phone(P4), not(nas(P4)), alv(P4), pal(P4).

underenglish([P1,P2],[affix,negative]):-

phone(P1),ctr(P1),str(P1),

phone(P2),nas(P2).

underenglish(A,[adjective,negative]):-

underenglish(B,[affix,negative]),

underenglish(C,[adjective]),

append(B,C,A).

english(A,B):-

underenglish(A,B),

(nas(N), cns(C), nextto(N,C,A)) => homorganic(N,C).

homorganic(A,B):-

lab(A) <=> lab(B),

dnt(A) <=> dnt(B),

alv(A) <=> alv(B),

pal(A) <=> pal(B),

vel(A) <=> vel(B).