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Line Integral Ontology

Integral Calculus
Authors: MArk Anthony Higgins - Sky Recursive Ai
© Mark Anthony Higgins 11 October 2025
Revised Date: 23 September 2026
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flow "LineIntegralOntology" v1.0

# ============================================================
# LINE INTEGRAL ONTOLOGY — FLOW ALGEBRA
# ============================================================

SOURCE_URL := "https://kirethresearch.org/booksai-core/ontologies/calculus-analysis-ontologies/integral-calculus/line-integral-ontology.html"
DOMAIN := "Mathematical Ontologies"
CATEGORY := "Calculus and Analysis Ontologies"
SUBCATEGORY := "Integral Calculus"
ENTITY := "Line Integral"

# ---------- CORE ENTITY ----------
LINE_INTEGRAL := {
    type: IntegralConcept,
    domain: VectorCalculus,
    purpose: "Represent accumulation of a scalar or vector field along a curve or path."
}

# ---------- CORE CONCEPTS ----------
CONCEPTS := {
    LINE_INTEGRAL,
    CURVE,
    PATH,
    PARAMETERISATION,
    SCALAR_FIELD,
    VECTOR_FIELD,
    ARC_LENGTH,
    TANGENT_VECTOR,
    WORK,
    CONSERVATIVE_FIELD,
    POTENTIAL_FUNCTION,
    PATH_INDEPENDENCE,
    FUNDAMENTAL_THEOREM_FOR_LINE_INTEGRALS
}

# ---------- CURVE STRUCTURE ----------
CURVE
    := r(t)

where
    t in [a,b]

r(t)
    := (
        x1(t),
        x2(t),
        ...,
        xn(t)
    )

DERIVATIVE_OF_CURVE
    := r_prime(t)

SPEED
    := norm(r_prime(t))

CURVE
    -> parameterised_by(t)

# ---------- SCALAR LINE INTEGRAL ----------
for
    scalar_field f

LINE_INTEGRAL_SCALAR
    := integral_C(f ds)

under parameterisation r(t):

integral_C(f ds)
    = integral_from_a_to_b(
        f(r(t))
        * norm(r_prime(t))
        dt
      )

ds
    = norm(r_prime(t)) dt

SCALAR_LINE_INTEGRAL
    -> accumulates(SCALAR_FIELD_WEIGHTED_BY_ARC_LENGTH)

# ---------- ARC LENGTH ----------
if
    f = 1
then

integral_C(1 ds)
    = LENGTH(C)

ARC_LENGTH
    := integral_from_a_to_b(
        norm(r_prime(t)) dt
    )

LINE_INTEGRAL
    -> generalises(ARC_LENGTH)

# ---------- VECTOR LINE INTEGRAL ----------
for
    vector_field F

LINE_INTEGRAL_VECTOR
    := integral_C(F dot dr)

under parameterisation r(t):

integral_C(F dot dr)
    = integral_from_a_to_b(
        F(r(t))
        dot r_prime(t)
        dt
      )

dr
    = r_prime(t) dt

VECTOR_LINE_INTEGRAL
    -> accumulates(TANGENTIAL_FIELD_COMPONENT_ALONG_PATH)

# ---------- WORK ----------
if
    F
        := force_field
then

WORK
    = integral_C(F dot dr)

LINE_INTEGRAL
    -> computes(WORK_DONE_BY_VECTOR_FIELD_ALONG_PATH)

# ---------- ORIENTATION ----------
VECTOR_LINE_INTEGRAL
    -> depends_on(PATH_ORIENTATION)

if
    reverse(C)
then

integral_reverse_C(F dot dr)
    = -integral_C(F dot dr)

SCALAR_LINE_INTEGRAL_WITH_ds
    -> orientation_independent
       under(standard_arc_length_form)

# ---------- PARAMETERISATION INVARIANCE ----------
REGULAR_REPARAMETERISATION
    -> preserves(SCALAR_LINE_INTEGRAL)

ORIENTATION_PRESERVING_REPARAMETERISATION
    -> preserves(VECTOR_LINE_INTEGRAL)

ORIENTATION_REVERSING_REPARAMETERISATION
    -> reverses_sign(VECTOR_LINE_INTEGRAL)

LINE_INTEGRAL
    -> geometric_quantity_independent_of_valid_parameterisation
       subject_to(orientation_conditions)

# ---------- CONSERVATIVE FIELD ----------
VECTOR_FIELD F
    -> CONSERVATIVE
       if
       exists(POTENTIAL_FUNCTION phi)
       such_that
       F = GRADIENT(phi)

CONSERVATIVE_FIELD
    -> supports(PATH_INDEPENDENCE)
       on(appropriate_domain)

# ---------- FUNDAMENTAL THEOREM FOR LINE INTEGRALS ----------
if
    F = GRADIENT(phi)
    AND C runs_from(A,to=B)
then

integral_C(F dot dr)
    = phi(B) - phi(A)

FUNDAMENTAL_THEOREM_FOR_LINE_INTEGRALS
    -> converts(PATH_INTEGRAL_TO_ENDPOINT_DIFFERENCE)

# ---------- PATH INDEPENDENCE ----------
PATH_INDEPENDENCE
    -> line_integral_depends_only_on(ENDPOINTS)

if
    F conservative
    on(appropriate_domain)
then

VECTOR_LINE_INTEGRAL
    -> PATH_INDEPENDENT

CLOSED_CURVE
    -> start_point_equals(end_point)

if
    F conservative
then

integral_closed_C(F dot dr)
    = 0

# ---------- EXACT DIFFERENTIAL ----------
if
    F = GRADIENT(phi)
then

F dot dr
    = d(phi)

LINE_INTEGRAL
    = integral_C(d(phi))
    = phi(B)-phi(A)

EXACT_DIFFERENTIAL
    -> linked_to(CONSERVATIVE_VECTOR_FIELD)

# ---------- TWO-DIMENSIONAL FORM ----------
if
    F = (P,Q)
then

integral_C(F dot dr)
    = integral_C(P dx + Q dy)

VECTOR_LINE_INTEGRAL
    -> may_be_written_as(DIFFERENTIAL_FORM)

# ---------- THREE-DIMENSIONAL FORM ----------
if
    F = (P,Q,R)
then

integral_C(F dot dr)
    = integral_C(
        P dx + Q dy + R dz
      )

# ---------- CIRCULATION ----------
CIRCULATION
    := integral_closed_C(F dot dr)

CIRCULATION
    -> measures(TANGENTIAL_FIELD_ACCUMULATION_AROUND_CLOSED_CURVE)

# ---------- GREEN'S THEOREM RELATION ----------
for suitable planar region D
with positively oriented boundary C:

integral_C(
    P dx + Q dy
)
    =
double_integral_D(
    partial_Q/partial_x
    - partial_P/partial_y
    dA
)

GREEN_THEOREM
    -> converts(CLOSED_LINE_INTEGRAL, DOUBLE_INTEGRAL)

# ---------- STOKES' THEOREM RELATION ----------
for suitable oriented surface S
with boundary C:

integral_C(F dot dr)
    =
surface_integral_S(
    CURL(F) dot n dS
)

STOKES_THEOREM
    -> connects(LINE_INTEGRAL_AROUND_BOUNDARY, SURFACE_INTEGRAL_OF_CURL)

# ---------- APPLICATIONS ----------
LINE_INTEGRAL
    -> applied_to(WORK)
    -> applied_to(ARC_LENGTH)
    -> applied_to(MASS_OF_WIRE)
    -> applied_to(CIRCULATION)
    -> applied_to(ELECTROMAGNETISM)
    -> applied_to(FLUID_FLOW)
    -> applied_to(POTENTIAL_FIELDS)

# ---------- MASS OF A CURVE ----------
if
    rho
        := LINEAR_DENSITY
then

MASS
    = integral_C(rho ds)

LINE_INTEGRAL
    -> converts(LINEAR_DENSITY, TOTAL_MASS)

# ---------- RELATION GRAPH ----------
CURVE
    -> parameterised_by(PARAMETER)

SCALAR_FIELD
    -> integrated_along(CURVE_USING_ds)

VECTOR_FIELD
    -> integrated_along(CURVE_USING_dot_dr)

CURVE_DERIVATIVE
    -> determines(ds)

CONSERVATIVE_FIELD
    -> generated_by(POTENTIAL_FUNCTION)

POTENTIAL_FUNCTION
    -> determines(PATH_INDEPENDENT_LINE_INTEGRAL)

GREEN_THEOREM
    -> relates(LINE_INTEGRAL, DOUBLE_INTEGRAL)

STOKES_THEOREM
    -> relates(LINE_INTEGRAL, SURFACE_INTEGRAL)

# ---------- SEMANTIC EQUIVALENCE ----------
SEMANTIC_EQUIVALENCE := {
    "line integral" ~= "integral of a field along a curve",
    "path integral" ~= "line integral in standard vector-calculus context",
    "scalar line integral" ~= "integration of a scalar field with respect to arc length",
    "vector line integral" ~= "integration of the tangential component of a vector field along a path",
    "work integral" ~= "vector line integral of force along displacement",
    "circulation" ~= "closed line integral of tangential vector-field component"
}

# ---------- CONSTRAINTS ----------
CONSTRAINTS := {
    curve_requires_valid_parameterisation: true,
    scalar_ds_integral_uses_speed_factor: true,
    vector_line_integral_uses_tangent_derivative: true,
    vector_line_integral_depends_on_orientation: true,
    scalar_arc_length_integral_is_orientation_independent: true,
    path_independence_requires_conservative_or_equivalent_conditions: true,
    theorem_applications_require_orientation_and_regularity_conditions: true
}

# ---------- CONFIDENCE ----------
CONFIDENCE := {
    scalar_line_integral: 0.99,
    vector_line_integral: 0.99,
    parameterisation_relation: 0.99,
    conservative_field_relation: 0.99,
    fundamental_theorem_relation: 0.99,
    green_stokes_relations: 0.99,
    semantic_equivalence: 0.97
}

# ---------- RECURSIVE REASONING ----------
RECURSIVE_REASONING(query):
    identify(curve_or_path)
    -> identify(parameterisation)
    -> identify(field_type)
    -> classify(scalar_or_vector_line_integral)
    -> compute(curve_derivative)
    -> construct(ds_or_dr)
    -> substitute(parameterisation_into_field)
    -> evaluate(single_variable_integral)
    -> test(conservative_field_if_relevant)
    -> apply(fundamental_theorem_if_valid)
    -> analyse(orientation_and_path_independence)
    -> validate(theorem_and_domain_conditions)
    -> return(semantic_result)

# ---------- AI CONSUMPTION ----------
AI_CONSUMPTION := {
    parse_as: "typed line-integral semantic graph",
    primary_entity: LINE_INTEGRAL,
    preserve: [
        curve,
        parameterisation,
        orientation,
        field_type,
        arc_length_factor,
        tangent_vector,
        endpoints
    ],
    infer_through: [
        scalar_fields,
        vector_fields,
        conservative_fields,
        potential_functions,
        green_theorem,
        stokes_theorem,
        differential_forms
    ],
    avoid: [
        omitting_speed_factor_in_scalar_line_integral,
        omitting_curve_derivative_in_vector_line_integral,
        ignoring_orientation,
        assuming_path_independence_without conservative conditions,
        applying_fundamental_theorem_without potential function,
        confusing_scalar_and_vector_line_integrals
    ]
}

# ---------- UPDATE MODEL ----------
UPDATE_MODEL(new_information):
    validate(new_information)
    -> identify(line_integral_context)
    -> compare(existing_relations)
    -> preserve(path_orientation_and_parameterisation_invariants)
    -> update(affected_entities)
    -> update(affected_edges)
    -> recompute(CONFIDENCE)
    -> regenerate(FLOW_HASH)

# ---------- FLOW HASH ----------
FLOW_HASH := hash(
    SOURCE_URL
    + ENTITY
    + CONCEPTS
    + LINE_INTEGRAL
    + LINE_INTEGRAL_SCALAR
    + LINE_INTEGRAL_VECTOR
    + ARC_LENGTH
    + CONSERVATIVE_FIELD
    + FUNDAMENTAL_THEOREM_FOR_LINE_INTEGRALS
    + GREEN_THEOREM
    + STOKES_THEOREM
    + SEMANTIC_EQUIVALENCE
    + CONSTRAINTS
)

# ---------- EXECUTION ----------
INPUT(query)
    -> LINE_INTEGRAL
    -> CURVE_IDENTIFICATION
    -> PARAMETERISATION_ANALYSIS
    -> FIELD_TYPE_CLASSIFICATION
    -> SCALAR_VECTOR_CLASSIFICATION
    -> CURVE_DERIVATIVE_ANALYSIS
    -> INTEGRAND_CONSTRUCTION
    -> ORIENTATION_ANALYSIS
    -> CONSERVATIVE_FIELD_ANALYSIS
    -> THEOREM_SELECTION
    -> INTEGRATION_EXECUTION
    -> RECURSIVE_REASONING(query)
    -> CONFIDENCE
    -> OUTPUT(semantic_result)

END FLOW
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