// from the block.
			removeBranch(parent, branch)
			// No point in considering the other branch.
			// (It *is* possible for both to be
			// unsatisfiable since the fact table is
			// incomplete. We could turn this into a
			// BlockExit, but it doesn't seem worth it.)
			break
		}
	}
}

func removeBranch(b *Block, branch branch) {
	c := b.Controls[0]