AssertionError at ProofTermGenerator.java:147 (check-allsat)

[rainoftime]

Hi, for the following formula,
147.txt

smtinterpol commit
cb90e74

sat
 (
   (IP_18 IP_4 IP_27 IP_10 IP_15)
 )
 ()
 ()
 ()
 ()
 Exception in thread "main" java.lang.AssertionError
        at de.uni_freiburg.informatik.ultimate.smtinterpol.proof.ProofTermGenerator.convert(ProofTermGenerator.java:147)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.SMTInterpol.getProof(SMTInterpol.java:799)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.SMTInterpol.getInterpolants(SMTInterpol.java:883)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.Parser$Action$.CUP$do_action(Parser.java:2933)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.Parser.do_action(Parser.java:1317)
        at com.github.jhoenicke.javacup.runtime.LRParser.parse(Unknown Source)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.ParseEnvironment.parseStream(ParseEnvironment.java:119)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.ParseEnvironment.parseScript(ParseEnvironment.java:98)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.smtlib2.SMTLIB2Parser.run(SMTLIB2Parser.java:35)
        at de.uni_freiburg.informatik.ultimate.smtinterpol.Main.main(Main.java:165)