{"id":521002,"date":"2026-07-24T10:48:00","date_gmt":"2026-07-24T10:48:00","guid":{"rendered":"https:\/\/livelycity.com\/switzerland\/arithmetic-formal-proof-for-1-times-1-1-mathematics\/"},"modified":"2026-07-24T10:48:00","modified_gmt":"2026-07-24T10:48:00","slug":"arithmetic-formal-proof-for-1-times-1-1-mathematics","status":"publish","type":"post","link":"https:\/\/livelycity.com\/switzerland\/arithmetic-formal-proof-for-1-times-1-1-mathematics\/","title":{"rendered":"arithmetic – Formal proof for $(-1) times (-1) = 1$ – Mathematics …"},"content":{"rendered":"

Is there a formal proof for $(-1) \\times (-1) = 1$? It’s a fundamental formula not only in arithmetic but also in the whole of math. Is there a proof for it or is it just assumed?<\/p>\n

\u00a0https:\/\/math.stackexchange.com\/questions\/304422\/formal-proof-for-1-times-1-1<\/a>\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

Is there a formal proof for $(-1) \\times (-1) = 1$? It’s a fundamental formula not only in arithmetic but also in the whole of…<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[8],"tags":[],"class_list":["post-521002","post","type-post","status-publish","format-standard","hentry","category-zurich","wpcat-8-id"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/posts\/521002","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/comments?post=521002"}],"version-history":[{"count":0,"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/posts\/521002\/revisions"}],"wp:attachment":[{"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/media?parent=521002"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/categories?post=521002"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/livelycity.com\/switzerland\/wp-json\/wp\/v2\/tags?post=521002"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}