In Visual Studio 2013, we can develop SharePoint 2013 workflow and deploy directly in SharePoint. However, once a workflow is deployed and later modified and redeployed, the modified workflow definition doesn't take effects. Even if you retract the solution and redeploy, the associated workflow with the sharepoint solution doesn't get updated in the SharePoint. Retracting the SharePoint solution then restarting the development server and finally redeploying will reset the workflow definition.