{"schema_version":"ocme-site-results-v1","locale":"en","page_type":"derivations","facts":{"questions":36000,"reviewed":36000,"display_candidates":0,"knowledge":302,"guides":299,"paths":59,"batches":360,"families":1441,"atlas":302,"core":80,"evidence":9,"formal_evidence":5,"formal_subjects":4,"lean_files":6,"lean_toolchain":"leanprover/lean4:v4.30.0","question_state":"candidate","english_state":"ai_candidate","question_Lean":"NOT_RUN","canonical_truth_promotion":false},"filters":{"q":"mko-lean-formal-statement"},"kind":"guides","total":1,"pages":1,"page":1,"entries":[{"id":"derivation-mko-lean-formal-statement-01","title":{"zh-Hant":"證明助理中的形式陳述：逐層讀懂一個 Lean 陳述並區分「是陳述」與「已證明」","en":"Formal statements in a proof assistant: reading a Lean statement layer by layer and separating 'is a statement' from 'is proved'"},"summary":{"zh-Hant":"以源碼字串 s：`∀ (a b : Nat), a ≤ b → a < b + 1` 為教學對象，在一個明示固定但未實際執行的環境 E 中逐層說明：它的約束變數與型別、假設與結論、若 elaboration 成功應得到的核心項 S、為何 S 的型別會是 Prop、一個證明項必須建立什麼；再給出其數學內容的非正式證明，並以 s′：`∀ (a : Nat), a - 1 < a`（是 Prop 但為假）與 s″：`∀ (a : Int), a - 1 < a`（為真）對照。全程未執行 Lean，不宣稱任何內容可解析、可 elaboration、已編譯或已被 Lean 證明。","en":"Take the source string s: `∀ (a b : Nat), a ≤ b → a < b + 1` as a teaching object and, in an environment E that is fixed explicitly but never executed, explain layer by layer: its bound variables and their types, its hypothesis and conclusion, the core term S that elaboration would have to produce if it succeeded, why S would have type Prop, and what a proof term would have to establish; then give an informal proof of its mathematical content and contrast it with s′: `∀ (a : Nat), a - 1 < a` (a Prop, but false) and s″: `∀ (a : Int), a - 1 < a` (true). Lean is not run at any point, and nothing here claims that any text parses, elaborates, compiles or is proved by Lean."},"mko_ids":["mko-lean-formal-statement"]}],"title":"Concept derivation guides"}