Adds singletons-presburger
Adds singletons-presburger

athanclark/stackage,fpco/stackage,asr/stackage,soenkehahn/stackage,stackbuilders/stackage,michalkonecny/stackage,clinty/stackage,jonschoning/stackage,mrkkrp/stackage,Daniel-Diaz/stackage,iand675/stackage,massysett/stackage,simonmichael/stackage