{"id":"cross-product-avoids-division-by-zero","text":"The collinearity check in `check-if-it-is-a-straight-line` uses cross-product multiplication `(x-x0)*dy - (y-y0)*dx == 0` rather than slope division, making it correct for vertical lines and exact for integer coordinates without epsilon tolerance.","truth_value":"IN","source":"entries/2026/06/06/check-if-it-is-a-straight-line-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"cross-product-avoids-division-by-zero","truth_value":"IN","reason":"premise"}]}}