coAxiomSingleBranch :: CoAxiom Unbranched -> CoAxBranch
coAxiomSingleBranch (CoAxiom { co_ax_branches = MkBranches arr })
  = arr ! 0
coAxiomSingleBranch :: CoAxiom Unbranched -> CoAxBranch
coAxiomSingleBranch (CoAxiom { co_ax_branches = MkBranches arr })
  = arr ! 0
coAxiomSingleBranch (CoAxiom { co_ax_branches = MkBranches arr })
  = arr ! 0