第 27823 題：梯度下降

原題與已知條件

standard Euclidean coordinate order、正步長與完整gradient update。操作=gd-boundary；明示資料={"mode":"finite_trace_only","model":{"diagonal":[1,2],"linear":[22,-22],"point":[23,1],"step_size":[1,4],"steps":1}}；請依 exact_ordered_tuple_declared_by_interface 回答。

• G001 — standard Euclidean coordinate order、正步長與完整gradient update。操作=gd-boundary；明示資料={"mode":"finite_trace_only","model":{"diagonal":[1,2],"linear":[22,-22],"point":[23,1],"step_size":[1,4],"steps":1}}；請依 exact_ordered_tuple_declared_by_interface 回答。

定義與適用範圍

沿用原題明示的論域、假設與來源 MKO 定義。本題已完成第二對話數理與中英語義覆核，並由原始參數逐題獨立重算模型、答案與每個算術步驟；原題仍為 candidate。

• mko-gradient-descent

逐步推導

source roles = [gd-boundary]

derived = [[mode, step_count, iterate_objective_records, convergence_or_global_optimality_claim, boundary]]

GD boundary ORIGINAL ORIGINAL gradient d*x coordinate0 := mul(1, 23)

GD boundary ORIGINAL ORIGINAL gradient d*x coordinate0 = 23

GD boundary ORIGINAL ORIGINAL gradient plus b coordinate0 := sum(23, 22)

GD boundary ORIGINAL ORIGINAL gradient plus b coordinate0 = 45

GD boundary ORIGINAL ORIGINAL gradient d*x coordinate1 := mul(2, 1)

GD boundary ORIGINAL ORIGINAL gradient d*x coordinate1 = 2

GD boundary ORIGINAL ORIGINAL gradient plus b coordinate1 := sum(2, -22)

GD boundary ORIGINAL ORIGINAL gradient plus b coordinate1 = -20

GD boundary ORIGINAL ORIGINAL objective SQUARE FIRST coordinate0 := mul(23, 23)

GD boundary ORIGINAL ORIGINAL objective SQUARE FIRST coordinate0 = 529

GD boundary ORIGINAL ORIGINAL diagonal times square coordinate0 := mul(1, 529)

GD boundary ORIGINAL ORIGINAL diagonal times square coordinate0 = 529

GD boundary ORIGINAL ORIGINAL quadratic divide2 coordinate0 := div(529, 2)

GD boundary ORIGINAL ORIGINAL quadratic divide2 coordinate0 = 529/2

GD boundary ORIGINAL ORIGINAL linear product coordinate0 := mul(22, 23)

GD boundary ORIGINAL ORIGINAL linear product coordinate0 = 506

GD boundary ORIGINAL ORIGINAL coordinate objective sum0 := sum(529/2, 506)

GD boundary ORIGINAL ORIGINAL coordinate objective sum0 = 1541/2

GD boundary ORIGINAL ORIGINAL objective running sum0 := sum(0, 1541/2)

GD boundary ORIGINAL ORIGINAL objective running sum0 = 1541/2

GD boundary ORIGINAL ORIGINAL objective SQUARE FIRST coordinate1 := mul(1, 1)

GD boundary ORIGINAL ORIGINAL objective SQUARE FIRST coordinate1 = 1

GD boundary ORIGINAL ORIGINAL diagonal times square coordinate1 := mul(2, 1)

GD boundary ORIGINAL ORIGINAL diagonal times square coordinate1 = 2

GD boundary ORIGINAL ORIGINAL quadratic divide2 coordinate1 := div(2, 2)

GD boundary ORIGINAL ORIGINAL quadratic divide2 coordinate1 = 1

GD boundary ORIGINAL ORIGINAL linear product coordinate1 := mul(-22, 1)

GD boundary ORIGINAL ORIGINAL linear product coordinate1 = -22

GD boundary ORIGINAL ORIGINAL coordinate objective sum1 := sum(1, -22)

GD boundary ORIGINAL ORIGINAL coordinate objective sum1 = -21

GD boundary ORIGINAL ORIGINAL objective running sum1 := sum(1541/2, -21)

GD boundary ORIGINAL ORIGINAL objective running sum1 = 1499/2

source roles = [GD boundary ORIGINAL, [1, 2], [22, -22], [23, 1]]

derived = [[1, 2], [22, -22], [23, 1], [45, -20], 1499/2]

GD boundary step1 ORIGINAL alpha times gradient0 := mul(1/4, 45)

GD boundary step1 ORIGINAL alpha times gradient0 = 45/4

GD boundary step1 ORIGINAL next coordinate0 := sub(23, 45/4)

GD boundary step1 ORIGINAL next coordinate0 = 47/4

GD boundary step1 ORIGINAL alpha times gradient1 := mul(1/4, -20)

GD boundary step1 ORIGINAL alpha times gradient1 = -5

GD boundary step1 ORIGINAL next coordinate1 := sub(1, -5)

GD boundary step1 ORIGINAL next coordinate1 = 6

GD boundary step1 next recomputation ORIGINAL gradient d*x coordinate0 := mul(1, 47/4)

GD boundary step1 next recomputation ORIGINAL gradient d*x coordinate0 = 47/4

GD boundary step1 next recomputation ORIGINAL gradient plus b coordinate0 := sum(47/4, 22)

GD boundary step1 next recomputation ORIGINAL gradient plus b coordinate0 = 135/4

GD boundary step1 next recomputation ORIGINAL gradient d*x coordinate1 := mul(2, 6)

GD boundary step1 next recomputation ORIGINAL gradient d*x coordinate1 = 12

GD boundary step1 next recomputation ORIGINAL gradient plus b coordinate1 := sum(12, -22)

GD boundary step1 next recomputation ORIGINAL gradient plus b coordinate1 = -10

GD boundary step1 next recomputation ORIGINAL objective SQUARE FIRST coordinate0 := mul(47/4, 47/4)

GD boundary step1 next recomputation ORIGINAL objective SQUARE FIRST coordinate0 = 2209/16

GD boundary step1 next recomputation ORIGINAL diagonal times square coordinate0 := mul(1, 2209/16)

GD boundary step1 next recomputation ORIGINAL diagonal times square coordinate0 = 2209/16

GD boundary step1 next recomputation ORIGINAL quadratic divide2 coordinate0 := div(2209/16, 2)

GD boundary step1 next recomputation ORIGINAL quadratic divide2 coordinate0 = 2209/32

GD boundary step1 next recomputation ORIGINAL linear product coordinate0 := mul(22, 47/4)

GD boundary step1 next recomputation ORIGINAL linear product coordinate0 = 517/2

GD boundary step1 next recomputation ORIGINAL coordinate objective sum0 := sum(2209/32, 517/2)

GD boundary step1 next recomputation ORIGINAL coordinate objective sum0 = 10481/32

GD boundary step1 next recomputation ORIGINAL objective running sum0 := sum(0, 10481/32)

GD boundary step1 next recomputation ORIGINAL objective running sum0 = 10481/32

GD boundary step1 next recomputation ORIGINAL objective SQUARE FIRST coordinate1 := mul(6, 6)

GD boundary step1 next recomputation ORIGINAL objective SQUARE FIRST coordinate1 = 36

GD boundary step1 next recomputation ORIGINAL diagonal times square coordinate1 := mul(2, 36)

GD boundary step1 next recomputation ORIGINAL diagonal times square coordinate1 = 72

GD boundary step1 next recomputation ORIGINAL quadratic divide2 coordinate1 := div(72, 2)

GD boundary step1 next recomputation ORIGINAL quadratic divide2 coordinate1 = 36

GD boundary step1 next recomputation ORIGINAL linear product coordinate1 := mul(-22, 6)

GD boundary step1 next recomputation ORIGINAL linear product coordinate1 = -132

GD boundary step1 next recomputation ORIGINAL coordinate objective sum1 := sum(36, -132)

GD boundary step1 next recomputation ORIGINAL coordinate objective sum1 = -96

GD boundary step1 next recomputation ORIGINAL objective running sum1 := sum(10481/32, -96)

GD boundary step1 next recomputation ORIGINAL objective running sum1 = 7409/32

source roles = [GD boundary step1 next recomputation, [[1, 1], [2, 1]], [[22, 1], [-22, 1]], [[47, 4], [6, 1]]]

derived = [[1, 2], [22, -22], [47/4, 6], [135/4, -10], 7409/32]

source roles = [1/4, 1]

derived = [[[0, [23, 1], 1499/2], [1, [47/4, 6], 7409/32]], 否]

逐步反向核對

• S040 · premise_and_result_audit — 回查原始資料、操作數、完整範圍與本步前提；有限見證、條件式定理引用與形式證明分開。
• S039 · premise_and_result_audit — 回查原始資料、操作數、完整範圍與本步前提；有限見證、條件式定理引用與形式證明分開。
• S038 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL objective running sum1，不以小數近似替代。
• S037 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL coordinate objective sum1，不以小數近似替代。
• S036 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL linear product coordinate1，不以小數近似替代。
• S035 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL quadratic divide2 coordinate1，不以小數近似替代。
• S034 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL diagonal times square coordinate1，不以小數近似替代。
• S033 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL objective SQUARE FIRST coordinate1，不以小數近似替代。
• S032 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL objective running sum0，不以小數近似替代。
• S031 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL coordinate objective sum0，不以小數近似替代。
• S030 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL linear product coordinate0，不以小數近似替代。
• S029 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL quadratic divide2 coordinate0，不以小數近似替代。
• S028 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL diagonal times square coordinate0，不以小數近似替代。
• S027 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL objective SQUARE FIRST coordinate0，不以小數近似替代。
• S026 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL gradient plus b coordinate1，不以小數近似替代。
• S025 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL gradient d*x coordinate1，不以小數近似替代。
• S024 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL gradient plus b coordinate0，不以小數近似替代。
• S023 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 next recomputation ORIGINAL gradient d*x coordinate0，不以小數近似替代。
• S022 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 ORIGINAL next coordinate1，不以小數近似替代。
• S021 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 ORIGINAL alpha times gradient1，不以小數近似替代。
• S020 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 ORIGINAL next coordinate0，不以小數近似替代。
• S019 · premise_and_result_audit — 以精確有理數重算 GD boundary step1 ORIGINAL alpha times gradient0，不以小數近似替代。
• S018 · premise_and_result_audit — 回查原始資料、操作數、完整範圍與本步前提；有限見證、條件式定理引用與形式證明分開。
• S017 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL objective running sum1，不以小數近似替代。
• S016 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL coordinate objective sum1，不以小數近似替代。
• S015 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL linear product coordinate1，不以小數近似替代。
• S014 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL quadratic divide2 coordinate1，不以小數近似替代。
• S013 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL diagonal times square coordinate1，不以小數近似替代。
• S012 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL objective SQUARE FIRST coordinate1，不以小數近似替代。
• S011 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL objective running sum0，不以小數近似替代。
• S010 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL coordinate objective sum0，不以小數近似替代。
• S009 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL linear product coordinate0，不以小數近似替代。
• S008 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL quadratic divide2 coordinate0，不以小數近似替代。
• S007 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL diagonal times square coordinate0，不以小數近似替代。
• S006 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL objective SQUARE FIRST coordinate0，不以小數近似替代。
• S005 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL gradient plus b coordinate1，不以小數近似替代。
• S004 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL gradient d*x coordinate1，不以小數近似替代。
• S003 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL gradient plus b coordinate0，不以小數近似替代。
• S002 · premise_and_result_audit — 以精確有理數重算 GD boundary ORIGINAL ORIGINAL gradient d*x coordinate0，不以小數近似替代。
• S001 · premise_and_result_audit — 回查原始資料、操作數、完整範圍與本步前提；有限見證、條件式定理引用與形式證明分開。

結論

(finite_trace_only, 1, [[0, [23, 1], 1499/2], [1, [47/4, 6], 7409/32]], 否, finite_trace_does_not_prove_convergence_or_global_optimality)

依上列完整代值及條件核對得到原題答案；原題編號、格式與狀態保持不變。

本題覆核與來源綁定

覆核日期：2026-10-26

原題、答案、步驟表達式、數值 AST 與既有歷史保持原樣；原來的候選狀態屬於來源歷史，不覆寫為形式化證明。