∃∃L2. G ⊢ L1 ⫃[RP] L2 & ⬇*[Ⓕ, des] L2 ≡ K2.
#RR #RS #RP #Hgcp #G #L1 #K1 #des #H elim H -L1 -K1 -des
[ /2 width=3 by drops_nil, ex2_intro/
∃∃L2. G ⊢ L1 ⫃[RP] L2 & ⬇*[Ⓕ, des] L2 ≡ K2.
#RR #RS #RP #Hgcp #G #L1 #K1 #des #H elim H -L1 -K1 -des
[ /2 width=3 by drops_nil, ex2_intro/