Step-by-step derivation
S001 · implies
Before
source roles = [qf-mod50-trap-error-boundary, trap-error-boundary]
After
derived = [[mode, individual_widths, correct_value, wrong_single_width_value, single_width_method_claim, boundary]]
Conditions: none
List this scalar/label/set/point answer role or mode-specific ordered fields,not an imposed universal tuple.Retain legacy domain/underscore operation and integer fractions with/1;original bilingual snapshots stay unchanged.
Step identifiers and dependencies
Rule: source_answer_roles_or_ordered_fields_without_JS · Uses: G001
S002 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL width0 := sub(1, 0)
After
Trapezoid boundary ORIGINAL ORIGINAL width0 = 1
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S001
S003 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL width1 := sub(26, 1)
After
Trapezoid boundary ORIGINAL ORIGINAL width1 = 25
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S002
S004 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL width over2 interval0 := div(1, 2)
After
Trapezoid boundary ORIGINAL ORIGINAL width over2 interval0 = 1/2
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S003
S005 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL endpoint sum interval0 := sum(23, 47)
After
Trapezoid boundary ORIGINAL ORIGINAL endpoint sum interval0 = 70
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S004
S006 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL individual trapezoid interval0 := mul(1/2, 70)
After
Trapezoid boundary ORIGINAL ORIGINAL individual trapezoid interval0 = 35
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S005
S007 · implies
Before
source roles = [Trapezoid boundary ORIGINAL, 0, 0, 1, 23, 47]
After
derived = [1, 1/2, 70, 35]
Conditions: none
Use the own width and aligned endpoints of this ORIGINAL interval times the endpoint average.Widths may differ and values may be negative;do not sort or replace all widths with the first.
Step identifiers and dependencies
Rule: Trapezoid_EACH_original_interval_own_width_and_aligned_endpoints · Uses: G001, S006
S008 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL width over2 interval1 := div(25, 2)
After
Trapezoid boundary ORIGINAL ORIGINAL width over2 interval1 = 25/2
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S007
S009 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL endpoint sum interval1 := sum(47, 73)
After
Trapezoid boundary ORIGINAL ORIGINAL endpoint sum interval1 = 120
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S008
S010 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL individual trapezoid interval1 := mul(25/2, 120)
After
Trapezoid boundary ORIGINAL ORIGINAL individual trapezoid interval1 = 1500
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S009
S011 · implies
Before
source roles = [Trapezoid boundary ORIGINAL, 1, 1, 26, 47, 73]
After
derived = [25, 25/2, 120, 1500]
Conditions: none
Use the own width and aligned endpoints of this ORIGINAL interval times the endpoint average.Widths may differ and values may be negative;do not sort or replace all widths with the first.
Step identifiers and dependencies
Rule: Trapezoid_EACH_original_interval_own_width_and_aligned_endpoints · Uses: G001, S010
S012 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL trapezoid running total0 := sum(0, 35)
After
Trapezoid boundary ORIGINAL ORIGINAL trapezoid running total0 = 35
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S011
S013 · calculation
Before
Trapezoid boundary ORIGINAL ORIGINAL trapezoid running total1 := sum(35, 1500)
After
Trapezoid boundary ORIGINAL ORIGINAL trapezoid running total1 = 1535
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S012
S014 · implies
Before
source roles = [Trapezoid boundary ORIGINAL, [0, 1, 26], [23, 47, 73]]
After
derived = [[0, 1, 26], [23, 47, 73], [1, 25], [35, 1500], 1535]
Conditions: none
A complete partition is STRICTLY increasing in original order,with n+1 aligned nodes/values for n intervals;the24-node cap is not the vector8 cap.The table determines this sum,not a unique integral without a full integrand.
Step identifiers and dependencies
Rule: Trapezoid_COMPLETE_partition_n_intervals_nplus1_nodes_no_unique_integrand · Uses: G001, S013
S015 · calculation
Before
Trapezoid wrongwidth ORIGINAL end values sum := sum(23, 73)
After
Trapezoid wrongwidth ORIGINAL end values sum = 96
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S014
S016 · calculation
Before
Trapezoid wrongwidth ORIGINAL end values half := div(96, 2)
After
Trapezoid wrongwidth ORIGINAL end values half = 48
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S015
S017 · calculation
Before
Trapezoid wrongwidth ORIGINAL interior sum0 := sum(0, 47)
After
Trapezoid wrongwidth ORIGINAL interior sum0 = 47
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S016
S018 · calculation
Before
Trapezoid wrongwidth ORIGINAL bracket := sum(48, 47)
After
Trapezoid wrongwidth ORIGINAL bracket = 95
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S017
S019 · calculation
Before
Trapezoid wrongwidth ORIGINAL FIRST width times bracket := mul(1, 95)
After
Trapezoid wrongwidth ORIGINAL FIRST width times bracket = 95
Conditions: none
Substitute original roles exactly,without floating approximation or changed operands;extra teaching identities add no source-domain restrictions.
Step identifiers and dependencies
Rule: exact_rational_arithmetic · Uses: G001, S018
S020 · implies
Before
source roles = [[1, 25], [23, 47, 73]]
After
derived = [1535, 95, No]
Conditions: none
Require at least two distinct widths AND actual numerical disagreement;an accidental equality or uniform partition is not this witness.
Step identifiers and dependencies
Rule: Trapezoid_ACTUAL_nonuniform_discriminating_first_width_error · Uses: G001, S019