GS3 failure: tried to apply a missing hypothesis when using `-inner` and `-preinner` flags

[jrosain]

Launching _build/goeland -ocoq [-inner|-preinner] problem.p ends up in a panic failure:

panic: [GS3] Failure: tried to apply a missing hypothesis

where problem.p is the following file:

fof(problem,conjecture,
    ~( ! [X,Y] : (
        (~p(Y) & ? [Z] : p(Z)) |
        (~q(X) & ? [Z2] : q(Z2))
       ))).