Erdős problem 196Must every permutation of N\mathbb{N}, contain a monotone 4-term arithmetic progression?WorkspaceContinue locallyOpen sourceSign in to contributeOpen this exact Problem, source revision, and authority Repository in Workbench. This handoff does not clone, switch, upload, or execute anything.FilesErdős problem 1962 retained source recordsCanvaspublic previewSource#196→ResultNone→Checks0