coAxiomNthBranch :: CoAxiom br -> BranchIndex -> CoAxBranch
coAxiomNthBranch (CoAxiom { co_ax_branches = bs }) index
  = branchesNth bs index
coAxiomNthBranch :: CoAxiom br -> BranchIndex -> CoAxBranch
coAxiomNthBranch (CoAxiom { co_ax_branches = bs }) index
  = branchesNth bs index
coAxiomNthBranch (CoAxiom { co_ax_branches = bs }) index
  = branchesNth bs index