{"id":"btree-traversal-is-forward-only","text":"B-tree sequential access is strictly forward-only: iteration descends the left spine (following children at index zero at every internal level) to reach the leftmost leaf, then walks the forward-only sibling chain, with no backward pointer, reverse iterator, or random leaf access mechanism.","truth_value":"IN","source":"","source_url":"","source_hash":"","justifications":[{"type":"SL","antecedents":["btree-leaf-sibling-chain-forward-only","iter-descends-left-spine"],"outlist":[],"label":"Both the descent path and horizontal walk are unidirectional, constraining all sequential access to forward traversal"}],"dependents":[],"metadata":{"last_reviewed":"2026-05-30T09:01:17","review_result":"pass"},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"btree-traversal-is-forward-only","truth_value":"IN","reason":"SL justification valid","antecedents":["btree-leaf-sibling-chain-forward-only","iter-descends-left-spine"],"label":"Both the descent path and horizontal walk are unidirectional, constraining all sequential access to forward traversal"},{"node":"btree-leaf-sibling-chain-forward-only","truth_value":"IN","reason":"premise"},{"node":"iter-descends-left-spine","truth_value":"IN","reason":"premise"}]}}