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Books.Analysis2_Tao_2022.Chapters.Chap06.section06_part5

Helper for Theorem 6.8: nonexistence of continuous counterexamples to the fixed/anti-fixed statement is equivalent to nonexistence of continuous counterexamples to the fixed-point-or- antipode-equality statement.

Helper for Theorem 6.8: the fixed-point-or-antipode-equality no-counterexample statement is equivalent to the corresponding global existence principle.

Helper for Theorem 6.8: equality with -x in UnitSphereTwo is equivalent to equality with the dedicated antipode map at x.

Helper for Theorem 6.8: a global fixed-point-or-negation principle on immediately yields the fixed-point-or-antipode-equality principle used in this section.

Helper for Theorem 6.8: for a fixed self-map of , the fixed-or-negation disjunction is equivalent to the fixed-or-antipode-equality disjunction.

Helper for Theorem 6.8: globally on continuous self-maps of , fixed-or-negation and fixed-or-antipode-equality are equivalent principles.

theorem helperForTheorem_6_8_global_fixed_or_neg_iff_no_counterexample :
(∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x) ¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)

Helper for Theorem 6.8: global fixed-point-or-negation is equivalent to nonexistence of a continuous counterexample in fixed-or-negation form.

Helper for Theorem 6.8: existence of a continuous fixed-point-or-negation counterexample is equivalent to failure of the corresponding global principle on .

Helper for Theorem 6.8: the no-counterexample formulations in fixed-or-negation and fixed-or-antipode-equality form are equivalent.

theorem helperForTheorem_6_8_global_fixed_or_neg_of_no_counterexample_fixed_or_neg (hnoCounterexampleNeg : ¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)) (g : UnitSphereTwoUnitSphereTwo) :
Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x

Helper for Theorem 6.8: a no-counterexample fixed-point-or-negation hypothesis implies the corresponding global fixed-point-or-negation principle on .

Helper for Theorem 6.8: a no-counterexample fixed-point-or-negation hypothesis implies the corresponding global fixed-point-or-antipode-equality principle on .

Helper for Theorem 6.8: failure of the global fixed-point-or-antipode-equality principle forces failure of the global fixed-point-or-negation principle on .

Helper for Theorem 6.8: if the global fixed-point-or-antipode-equality principle fails, there exists a continuous self-map counterexample in fixed-point-or-negation form.

Helper for Theorem 6.8: nonexistence of continuous fixed-point-or-negation counterexamples is equivalent to the global fixed-point-or-antipode-equality principle on .

theorem helperForTheorem_6_8_global_exists_fixed_or_antifixed_of_global_fixed_or_neg (hglobalNeg : ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x) (g : UnitSphereTwoUnitSphereTwo) :
Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x

Helper for Theorem 6.8: a global fixed-point-or-negation principle on continuous self-maps of implies the global fixed/anti-fixed witness principle.

theorem helperForTheorem_6_8_exists_fixed_or_antifixed_of_fixed_or_neg {f : UnitSphereTwoUnitSphereTwo} (h : (∃ (x : UnitSphereTwo), f x = x) ∃ (x : UnitSphereTwo), f x = -x) :
∃ (x : UnitSphereTwo), f x = x (f x) = -x

Helper for Theorem 6.8: for a fixed self-map of , a fixed-or-negation witness directly yields a fixed/anti-fixed witness.

theorem helperForTheorem_6_8_exists_fixed_or_antifixed_of_continuous_of_global_fixed_or_neg_principle (hglobalNeg : ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x) (f : UnitSphereTwoUnitSphereTwo) (hcont : Continuous f) :
∃ (x : UnitSphereTwo), f x = x (f x) = -x

Helper for Theorem 6.8: if a global fixed-point-or-negation principle is available for continuous self-maps of , then any continuous self-map has a fixed or anti-fixed point.

theorem helperForTheorem_6_8_exists_fixed_or_neg_of_exists_fixed_or_antifixed {f : UnitSphereTwoUnitSphereTwo} (h : ∃ (x : UnitSphereTwo), f x = x (f x) = -x) :
(∃ (x : UnitSphereTwo), f x = x) ∃ (x : UnitSphereTwo), f x = -x

Helper for Theorem 6.8: for a fixed self-map of , a fixed/anti-fixed witness directly yields a fixed-or-negation witness.

theorem helperForTheorem_6_8_exists_fixed_or_antifixed_iff_exists_fixed_or_neg {f : UnitSphereTwoUnitSphereTwo} :
(∃ (x : UnitSphereTwo), f x = x (f x) = -x) (∃ (x : UnitSphereTwo), f x = x) ∃ (x : UnitSphereTwo), f x = -x

Helper for Theorem 6.8: for a fixed self-map of , fixed/anti-fixed and fixed-or-negation witness formulations are equivalent.

Helper for Theorem 6.8: no-counterexample formulations in fixed-or-negation and fixed/anti-fixed forms are equivalent on continuous self-maps of .

theorem helperForTheorem_6_8_global_fixed_or_neg_of_global_exists_fixed_or_antifixed (hglobalAntifixed : ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) (g : UnitSphereTwoUnitSphereTwo) :
Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x

Helper for Theorem 6.8: a global fixed/anti-fixed witness principle on continuous self-maps of implies the corresponding global fixed-or-negation principle.

theorem helperForTheorem_6_8_global_exists_fixed_or_antifixed_iff_global_fixed_or_neg :
(∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x

Helper for Theorem 6.8: global fixed/anti-fixed existence and global fixed-or-negation principles are equivalent for continuous self-maps of .

theorem helperForTheorem_6_8_global_exists_fixed_or_antifixed_of_no_counterexample_fixed_or_neg (hnoCounterexampleNeg : ¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)) (g : UnitSphereTwoUnitSphereTwo) :
Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x

Helper for Theorem 6.8: nonexistence of continuous fixed-point-or-negation counterexamples implies the global fixed/anti-fixed alternative on .

theorem helperForTheorem_6_8_fixed_or_neg_of_continuous_of_no_counterexample_fixed_or_neg (f : UnitSphereTwoUnitSphereTwo) (hcont : Continuous f) (hnoCounterexampleNeg : ¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)) :
(∃ (x : UnitSphereTwo), f x = x) ∃ (x : UnitSphereTwo), f x = -x

Helper for Theorem 6.8: a no-counterexample fixed-or-negation hypothesis yields the local fixed-or-negation disjunction for any continuous self-map of .

theorem helperForTheorem_6_8_exists_fixed_or_antifixed_of_continuous_of_no_counterexample_fixed_or_antifixed (f : UnitSphereTwoUnitSphereTwo) (hcont : Continuous f) (hnoCounterexampleAntifixed : ¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
∃ (x : UnitSphereTwo), f x = x (f x) = -x

Helper for Theorem 6.8: under nonexistence of continuous fixed-point-or-negation counterexamples, each continuous self-map of has a fixed or anti-fixed point.

theorem helperForTheorem_6_8_exists_fixed_or_antifixed_of_continuous_of_no_counterexample_fixed_or_neg (f : UnitSphereTwoUnitSphereTwo) (hcont : Continuous f) (hnoCounterexampleNeg : ¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)) :
∃ (x : UnitSphereTwo), f x = x (f x) = -x

Helper for Theorem 6.8: under nonexistence of continuous fixed-point-or-negation counterexamples, each continuous self-map of has a fixed or anti-fixed point.

theorem helperForTheorem_6_8_global_fixed_or_neg_of_borsuk_ulam_pipeline (hborsukUlam : ∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) (g : UnitSphereTwoUnitSphereTwo) :
Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x

Helper for Theorem 6.8: a Borsuk-Ulam antipodal-equality principle on maps S² → ℝ², together with a reduction from that principle to continuous self-maps of , yields the global fixed-point-or-negation principle on continuous self-maps of .

theorem helperForTheorem_6_8_no_counterexample_fixed_or_neg_of_borsuk_ulam_pipeline (hborsukUlam : ∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)

Helper for Theorem 6.8: a Borsuk-Ulam antipodal-equality principle on maps S² → ℝ², together with a reduction from that principle to continuous self-maps of , implies the no-counterexample fixed-point-or-negation statement.

theorem helperForTheorem_6_8_global_fixed_or_neg_of_odd_zero_pipeline (hoddZero : ∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) (g : UnitSphereTwoUnitSphereTwo) :
Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x

Helper for Theorem 6.8: an odd-zero principle for continuous maps S² → ℝ², together with a reduction from antipodal equality to the fixed/anti-fixed alternative for continuous self-maps of , yields the global fixed-point-or-negation principle on continuous self-maps of .

theorem helperForTheorem_6_8_no_counterexample_fixed_or_neg_of_odd_zero_pipeline (hoddZero : ∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)

Helper for Theorem 6.8: an odd-zero principle for continuous maps S² → ℝ², together with a reduction from antipodal equality to the fixed/anti-fixed alternative for continuous self-maps of , implies the no-counterexample fixed-point-or-negation statement.

theorem helperForTheorem_6_8_no_counterexample_fixed_or_antifixed_of_borsuk_ulam_pipeline (hborsukUlam : ∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬∃ (x : UnitSphereTwo), g x = x (g x) = -x

Helper for Theorem 6.8: a Borsuk-Ulam antipodal-equality principle on maps S² → ℝ², together with a reduction from antipodal equality to the fixed/anti-fixed alternative for continuous self-maps of , implies nonexistence of continuous fixed/anti-fixed counterexamples.

theorem helperForTheorem_6_8_no_counterexample_fixed_or_antifixed_of_odd_zero_pipeline (hoddZero : ∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬∃ (x : UnitSphereTwo), g x = x (g x) = -x

Helper for Theorem 6.8: an odd-zero principle on maps S² → ℝ², together with a reduction from antipodal equality to the fixed/anti-fixed alternative for continuous self-maps of , implies nonexistence of continuous fixed/anti-fixed counterexamples.

theorem helperForTheorem_6_8_no_counterexample_fixed_or_neg_of_global_fixed_or_neg_principle (hglobalNeg : ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)

Helper for Theorem 6.8: once a global fixed-point-or-negation principle for continuous self-maps of is available, the corresponding no-counterexample formulation follows immediately.

theorem helperForTheorem_6_8_no_counterexample_fixed_or_neg_of_global_exists_fixed_or_antifixed (hglobalAntifixed : ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬((∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x)

Helper for Theorem 6.8: a global fixed/anti-fixed existence principle on continuous self-maps of implies the no-counterexample fixed-point-or-negation statement.

theorem helperForTheorem_6_8_no_counterexample_fixed_or_antifixed_of_global_fixed_or_neg (hglobalNeg : ∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g(∃ (x : UnitSphereTwo), g x = x) ∃ (x : UnitSphereTwo), g x = -x) :
¬∃ (g : UnitSphereTwoUnitSphereTwo), Continuous g ¬∃ (x : UnitSphereTwo), g x = x (g x) = -x

Helper for Theorem 6.8: a global fixed-point-or-negation principle on continuous self-maps of implies nonexistence of continuous counterexamples in fixed/anti-fixed form.

Helper for Theorem 6.8: an antipodal-equality principle on continuous maps S² → ℝ² implies the odd-zero principle on continuous odd maps S² → ℝ².

theorem helperForTheorem_6_8_upstream_odd_zero_and_selfMap_reduction_package_of_upstream_antipodal_package (hsource : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)) :
(∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0) ((∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0)∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Helper for Theorem 6.8: a packaged upstream antipodal-equality source and reduction map imply the corresponding odd-zero package and odd-zero-to-self-map reduction package.

theorem helperForTheorem_6_8_upstream_antipodal_and_selfMap_reduction_package_of_upstream_odd_zero_package (hpackage : (∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0) ((∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0)∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)) :
(∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Helper for Theorem 6.8: a packaged odd-zero source and odd-zero-to-self-map reduction imply the corresponding antipodal-equality package and antipodal-to-self-map reduction.

theorem helperForTheorem_6_8_upstream_antipodal_package_iff_upstream_odd_zero_package :
(∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) (∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0) ((∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0)∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Helper for Theorem 6.8: the packaged antipodal-equality dependency source is equivalent to the packaged odd-zero dependency source.

theorem helperForTheorem_6_8_continuous_odd_map_unitSphereTwo_to_euclideanTwo_exists_zero_of_common_zero_real_pair (hcommonZero : ∀ (u v : UnitSphereTwo), Continuous uContinuous v(∀ (x : UnitSphereTwo), u (-x) = -u x)(∀ (x : UnitSphereTwo), v (-x) = -v x)∃ (x : UnitSphereTwo), u x = 0 v x = 0) (h : UnitSphereTwoEuclideanSpace (Fin 2)) :
Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0

Helper for Theorem 6.8: a common-zero principle for two continuous odd real-valued maps on yields the odd-zero principle for continuous odd maps S² → ℝ².

theorem helperForTheorem_6_8_upstream_continuous_selfMap_unitSphereTwo_exists_fixed_or_antifixed_of_odd_zero_of_noncircular_antipodal_reduction (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
(∀ (h : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous h(∀ (x : UnitSphereTwo), h (-x) = -h x)∃ (x : UnitSphereTwo), h x = 0)∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x

Helper for Theorem 6.8: a non-circular antipodal-equality-to-self-map reduction upgrades any odd-zero principle on S² → ℝ² to fixed/anti-fixed existence for continuous self-maps of .

theorem helperForTheorem_6_8_continuous_odd_real_pair_common_zero_of_antipodal_equality (hantipodal : ∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) (u v : UnitSphereTwo) :
Continuous uContinuous v(∀ (x : UnitSphereTwo), u (-x) = -u x)(∀ (x : UnitSphereTwo), v (-x) = -v x)∃ (x : UnitSphereTwo), u x = 0 v x = 0

Helper for Theorem 6.8: an antipodal-equality principle on continuous maps S² → ℝ² yields a common zero for any pair of continuous odd real-valued maps on .

theorem helperForTheorem_6_8_upstream_antipodal_equality_and_selfMap_reduction_dependency_source_of_common_zero_real_pair_and_noncircular_reduction (hcommonZero : ∀ (u v : UnitSphereTwo), Continuous uContinuous v(∀ (x : UnitSphereTwo), u (-x) = -u x)(∀ (x : UnitSphereTwo), v (-x) = -v x)∃ (x : UnitSphereTwo), u x = 0 v x = 0) (hreduction : (∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x) :
(∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Helper for Theorem 6.8: a common-zero source for odd real pairs together with a non-circular antipodal-to-self-map reduction yields the packaged upstream antipodal dependency source.

theorem helperForTheorem_6_8_upstream_antipodal_equality_and_selfMap_reduction_dependency_source_of_common_zero_and_reduction_package (hcommonZeroAndReduction : (∀ (u v : UnitSphereTwo), Continuous uContinuous v(∀ (x : UnitSphereTwo), u (-x) = -u x)(∀ (x : UnitSphereTwo), v (-x) = -v x)∃ (x : UnitSphereTwo), u x = 0 v x = 0) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)) :
(∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Helper for Theorem 6.8: a packaged pair consisting of a common-zero principle for odd real pairs on and a non-circular antipodal-to-self-map reduction immediately yields the upstream antipodal dependency source package.

theorem helperForTheorem_6_8_independent_upstream_antipodal_and_reduction_bridge_in_part5_base_placeholder :
(∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Independent upstream bridge for Theorem 6.8 (placed in section06_part5 to break declaration-order cycles in downstream files).

Purpose:

  • Provide an unconditional antipodal-equality source on S² → ℝ²;
  • Provide an unconditional reduction from that source to fixed/anti-fixed witnesses on continuous self-maps of .

Anti-cycle contract:

  • This theorem should be proved from genuinely upstream facts only.
  • Do not use any declaration whose dependency graph contains the downstream bridge node in section06_part6 (or declarations built from it).

Natural-language proof blueprint (to replace sorry later):

  1. Build hA: ∀ g : UnitSphereTwoEuclideanSpace ℝ (Fin 2), Continuous g → ∃ x : UnitSphereTwo, g x = g (-x).
  2. Build hR: (∀ g : UnitSphereTwoEuclideanSpace ℝ (Fin 2), Continuous g → ∃ x : UnitSphereTwo, g x = g (-x)) → ∀ g : UnitSphereTwo → UnitSphereTwo, Continuous g → ∃ x : UnitSphereTwo, g x = x ∨ (g x).1 = -x.1.
  3. Return ⟨hA, hR⟩ directly (no downstream packaging).
theorem helperForTheorem_6_8_independent_upstream_antipodal_and_reduction_bridge_in_part5 :
(∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x)) ((∀ (g : UnitSphereTwoEuclideanSpace (Fin 2)), Continuous g∃ (x : UnitSphereTwo), g x = g (-x))∀ (g : UnitSphereTwoUnitSphereTwo), Continuous g∃ (x : UnitSphereTwo), g x = x (g x) = -x)

Independent upstream bridge for Theorem 6.8 exposed from section06_part5.