P. 353 of Theorem List - Metamath Proof Explorer

Theorem List for Metamath Proof Explorer - 35201-35300   *Has distinct variable group(s)

Type	Label	Description
Statement
Theorem	lflf 35201	A linear functional is a function from vectors to scalars. (lnfnfi 29472 analog.) (Contributed by NM, 15-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑋 ∧ 𝐺 ∈ 𝐹) → 𝐺:𝑉⟶𝐾)
Theorem	lflcl 35202	A linear functional value is a scalar. (Contributed by NM, 15-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑌 ∧ 𝐺 ∈ 𝐹 ∧ 𝑋 ∈ 𝑉) → (𝐺‘𝑋) ∈ 𝐾)
Theorem	lfl0 35203	A linear functional is zero at the zero vector. (lnfn0i 29473 analog.) (Contributed by NM, 16-Apr-2014.) (Revised by Mario Carneiro, 24-Jun-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝑍 = (0g‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝐺 ∈ 𝐹) → (𝐺‘𝑍) = 0 )
Theorem	lfladd 35204	Property of a linear functional. (lnfnaddi 29474 analog.) (Contributed by NM, 18-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ ⨣ = (+g‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝐺 ∈ 𝐹 ∧ (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) → (𝐺‘(𝑋 + 𝑌)) = ((𝐺‘𝑋) ⨣ (𝐺‘𝑌)))
Theorem	lflsub 35205	Property of a linear functional. (lnfnaddi 29474 analog.) (Contributed by NM, 18-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝑀 = (-g‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ − = (-g‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝐺 ∈ 𝐹 ∧ (𝑋 ∈ 𝑉 ∧ 𝑌 ∈ 𝑉)) → (𝐺‘(𝑋 − 𝑌)) = ((𝐺‘𝑋)𝑀(𝐺‘𝑌)))
Theorem	lflmul 35206	Property of a linear functional. (lnfnmuli 29475 analog.) (Contributed by NM, 16-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ × = (.r‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝐺 ∈ 𝐹 ∧ (𝑅 ∈ 𝐾 ∧ 𝑋 ∈ 𝑉)) → (𝐺‘(𝑅 · 𝑋)) = (𝑅 × (𝐺‘𝑋)))
Theorem	lfl0f 35207	The zero function is a functional. (Contributed by NM, 16-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ (𝑊 ∈ LMod → (𝑉 × { 0 }) ∈ 𝐹)
Theorem	lfl1 35208*	A nonzero functional has a value of 1 at some argument. (Contributed by NM, 16-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 1 = (1r‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ 𝐺 ∈ 𝐹 ∧ 𝐺 ≠ (𝑉 × { 0 })) → ∃𝑥 ∈ 𝑉 (𝐺‘𝑥) = 1 )
Theorem	lfladdcl 35209	Closure of addition of two functionals. (Contributed by NM, 19-Oct-2014.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 + 𝐻) ∈ 𝐹)
Theorem	lfladdcom 35210	Commutativity of functional addition. (Contributed by NM, 19-Oct-2014.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 + 𝐻) = (𝐻 ∘𝑓 + 𝐺))
Theorem	lfladdass 35211	Associativity of functional addition. (Contributed by NM, 19-Oct-2014.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐼 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐺 ∘𝑓 + 𝐻) ∘𝑓 + 𝐼) = (𝐺 ∘𝑓 + (𝐻 ∘𝑓 + 𝐼)))
Theorem	lfladd0l 35212	Functional addition with the zero functional. (Contributed by NM, 21-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 0 = (0g‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝑉 × { 0 }) ∘𝑓 + 𝐺) = 𝐺)
Theorem	lflnegcl 35213*	Closure of the negative of a functional. (This is specialized for the purpose of proving ldualgrp 35284, and we do not define a general operation here.) (Contributed by NM, 22-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐼 = (invg‘𝑅)    &   ⊢ 𝑁 = (𝑥 ∈ 𝑉 ↦ (𝐼‘(𝐺‘𝑥)))    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → 𝑁 ∈ 𝐹)
Theorem	lflnegl 35214*	A functional plus its negative is the zero functional. (This is specialized for the purpose of proving ldualgrp 35284, and we do not define a general operation here.) (Contributed by NM, 22-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐼 = (invg‘𝑅)    &   ⊢ 𝑁 = (𝑥 ∈ 𝑉 ↦ (𝐼‘(𝐺‘𝑥)))    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 0 = (0g‘𝑅)    ⇒   ⊢ (𝜑 → (𝑁 ∘𝑓 + 𝐺) = (𝑉 × { 0 }))
Theorem	lflvscl 35215	Closure of a scalar product with a functional. Note that this is the scalar product for a right vector space with the scalar after the vector; reversing these fails closure. (Contributed by NM, 9-Oct-2014.) (Revised by Mario Carneiro, 22-Apr-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑅 ∈ 𝐾)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 · (𝑉 × {𝑅})) ∈ 𝐹)
Theorem	lflvsdi1 35216	Distributive law for (right vector space) scalar product of functionals. (Contributed by NM, 19-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐺 ∘𝑓 + 𝐻) ∘𝑓 · (𝑉 × {𝑋})) = ((𝐺 ∘𝑓 · (𝑉 × {𝑋})) ∘𝑓 + (𝐻 ∘𝑓 · (𝑉 × {𝑋}))))
Theorem	lflvsdi2 35217	Reverse distributive law for (right vector space) scalar product of functionals. (Contributed by NM, 19-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 · ((𝑉 × {𝑋}) ∘𝑓 + (𝑉 × {𝑌}))) = ((𝐺 ∘𝑓 · (𝑉 × {𝑋})) ∘𝑓 + (𝐺 ∘𝑓 · (𝑉 × {𝑌}))))
Theorem	lflvsdi2a 35218	Reverse distributive law for (right vector space) scalar product of functionals. (Contributed by NM, 21-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ + = (+g‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 · (𝑉 × {(𝑋 + 𝑌)})) = ((𝐺 ∘𝑓 · (𝑉 × {𝑋})) ∘𝑓 + (𝐺 ∘𝑓 · (𝑉 × {𝑌}))))
Theorem	lflvsass 35219	Associative law for (right vector space) scalar product of functionals. (Contributed by NM, 19-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 · (𝑉 × {(𝑋 · 𝑌)})) = ((𝐺 ∘𝑓 · (𝑉 × {𝑋})) ∘𝑓 · (𝑉 × {𝑌})))
Theorem	lfl0sc 35220	The (right vector space) scalar product of a functional with zero is the zero functional. Note that the first occurrence of (𝑉 × { 0 }) represents the zero scalar, and the second is the zero functional. (Contributed by NM, 7-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 · (𝑉 × { 0 })) = (𝑉 × { 0 }))
Theorem	lflsc0N 35221	The scalar product with the zero functional is the zero functional. (Contributed by NM, 7-Oct-2014.) (New usage is discouraged.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    ⇒   ⊢ (𝜑 → ((𝑉 × { 0 }) ∘𝑓 · (𝑉 × {𝑋})) = (𝑉 × { 0 }))
Theorem	lfl1sc 35222	The (right vector space) scalar product of a functional with one is the functional. (Contributed by NM, 21-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 1 = (1r‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ∘𝑓 · (𝑉 × { 1 })) = 𝐺)
Syntax	clk 35223	Extend class notation with the kernel of a functional (set of vectors whose functional value is zero) on a left module or left vector space.
class LKer
Definition	df-lkr 35224*	Define the kernel of a functional (set of vectors whose functional value is zero) on a left module or left vector space. (Contributed by NM, 15-Apr-2014.)
⊢ LKer = (𝑤 ∈ V ↦ (𝑓 ∈ (LFnl‘𝑤) ↦ (◡𝑓 “ {(0g‘(Scalar‘𝑤))})))
Theorem	lkrfval 35225*	The kernel of a functional. (Contributed by NM, 15-Apr-2014.) (Revised by Mario Carneiro, 24-Jun-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ (𝑊 ∈ 𝑋 → 𝐾 = (𝑓 ∈ 𝐹 ↦ (◡𝑓 “ { 0 })))
Theorem	lkrval 35226	Value of the kernel of a functional. (Contributed by NM, 15-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑋 ∧ 𝐺 ∈ 𝐹) → (𝐾‘𝐺) = (◡𝐺 “ { 0 }))
Theorem	ellkr 35227	Membership in the kernel of a functional. (elnlfn 29359 analog.) (Contributed by NM, 16-Apr-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑌 ∧ 𝐺 ∈ 𝐹) → (𝑋 ∈ (𝐾‘𝐺) ↔ (𝑋 ∈ 𝑉 ∧ (𝐺‘𝑋) = 0 )))
Theorem	lkrval2 35228*	Value of the kernel of a functional. (Contributed by NM, 15-Apr-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑋 ∧ 𝐺 ∈ 𝐹) → (𝐾‘𝐺) = {𝑥 ∈ 𝑉 ∣ (𝐺‘𝑥) = 0 })
Theorem	ellkr2 35229	Membership in the kernel of a functional. (Contributed by NM, 12-Jan-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑌)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    ⇒   ⊢ (𝜑 → (𝑋 ∈ (𝐾‘𝐺) ↔ (𝐺‘𝑋) = 0 ))
Theorem	lkrcl 35230	A member of the kernel of a functional is a vector. (Contributed by NM, 16-Apr-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑌 ∧ 𝐺 ∈ 𝐹 ∧ 𝑋 ∈ (𝐾‘𝐺)) → 𝑋 ∈ 𝑉)
Theorem	lkrf0 35231	The value of a functional at a member of its kernel is zero. (Contributed by NM, 16-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ 𝑌 ∧ 𝐺 ∈ 𝐹 ∧ 𝑋 ∈ (𝐾‘𝐺)) → (𝐺‘𝑋) = 0 )
Theorem	lkr0f 35232	The kernel of the zero functional is the set of all vectors. (Contributed by NM, 17-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝐺 ∈ 𝐹) → ((𝐾‘𝐺) = 𝑉 ↔ 𝐺 = (𝑉 × { 0 })))
Theorem	lkrlss 35233	The kernel of a linear functional is a subspace. (nlelshi 29491 analog.) (Contributed by NM, 16-Apr-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ 𝑆 = (LSubSp‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LMod ∧ 𝐺 ∈ 𝐹) → (𝐾‘𝐺) ∈ 𝑆)
Theorem	lkrssv 35234	The kernel of a linear functional is a set of vectors. (Contributed by NM, 1-Jan-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐾‘𝐺) ⊆ 𝑉)
Theorem	lkrsc 35235	The kernel of a nonzero scalar product of a functional equals the kernel of the functional. (Contributed by NM, 9-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐿 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑅 ∈ 𝐾)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑅 ≠ 0 )    ⇒   ⊢ (𝜑 → (𝐿‘(𝐺 ∘𝑓 · (𝑉 × {𝑅}))) = (𝐿‘𝐺))
Theorem	lkrscss 35236	The kernel of a scalar product of a functional includes the kernel of the functional. (The inclusion is proper for the zero product and equality otherwise.) (Contributed by NM, 9-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐿 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑅 ∈ 𝐾)    ⇒   ⊢ (𝜑 → (𝐿‘𝐺) ⊆ (𝐿‘(𝐺 ∘𝑓 · (𝑉 × {𝑅}))))
Theorem	eqlkr 35237*	Two functionals with the same kernel are the same up to a constant. (Contributed by NM, 18-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐿 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ (𝐺 ∈ 𝐹 ∧ 𝐻 ∈ 𝐹) ∧ (𝐿‘𝐺) = (𝐿‘𝐻)) → ∃𝑟 ∈ 𝐾 ∀𝑥 ∈ 𝑉 (𝐻‘𝑥) = ((𝐺‘𝑥) · 𝑟))
Theorem	eqlkr2 35238*	Two functionals with the same kernel are the same up to a constant. (Contributed by NM, 10-Oct-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐿 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ (𝐺 ∈ 𝐹 ∧ 𝐻 ∈ 𝐹) ∧ (𝐿‘𝐺) = (𝐿‘𝐻)) → ∃𝑟 ∈ 𝐾 𝐻 = (𝐺 ∘𝑓 · (𝑉 × {𝑟})))
Theorem	eqlkr3 35239	Two functionals with the same kernel are equal if they are equal at any nonzero value. (Contributed by NM, 2-Jan-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑆 = (Scalar‘𝑊)    &   ⊢ 𝑅 = (Base‘𝑆)    &   ⊢ 0 = (0g‘𝑆)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    &   ⊢ (𝜑 → (𝐾‘𝐺) = (𝐾‘𝐻))    &   ⊢ (𝜑 → (𝐺‘𝑋) = (𝐻‘𝑋))    &   ⊢ (𝜑 → (𝐺‘𝑋) ≠ 0 )    ⇒   ⊢ (𝜑 → 𝐺 = 𝐻)
Theorem	lkrlsp 35240	The subspace sum of a kernel and the span of a vector not in the kernel (by ellkr 35227) is the whole vector space. (Contributed by NM, 19-Apr-2014.)
⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ (𝑋 ∈ 𝑉 ∧ 𝐺 ∈ 𝐹) ∧ (𝐺‘𝑋) ≠ 0 ) → ((𝐾‘𝐺) ⊕ (𝑁‘{𝑋})) = 𝑉)
Theorem	lkrlsp2 35241	The subspace sum of a kernel and the span of a vector not in the kernel is the whole vector space. (Contributed by NM, 12-May-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ (𝑋 ∈ 𝑉 ∧ 𝐺 ∈ 𝐹) ∧ ¬ 𝑋 ∈ (𝐾‘𝐺)) → ((𝐾‘𝐺) ⊕ (𝑁‘{𝑋})) = 𝑉)
Theorem	lkrlsp3 35242	The subspace sum of a kernel and the span of a vector not in the kernel is the whole vector space. (Contributed by NM, 29-Jun-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ (𝑋 ∈ 𝑉 ∧ 𝐺 ∈ 𝐹) ∧ ¬ 𝑋 ∈ (𝐾‘𝐺)) → (𝑁‘((𝐾‘𝐺) ∪ {𝑋})) = 𝑉)
Theorem	lkrshp 35243	The kernel of a nonzero functional is a hyperplane. (Contributed by NM, 29-Jun-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ 𝐺 ∈ 𝐹 ∧ 𝐺 ≠ (𝑉 × { 0 })) → (𝐾‘𝐺) ∈ 𝐻)
Theorem	lkrshp3 35244	The kernels of nonzero functionals are hyperplanes. (Contributed by NM, 17-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐾‘𝐺) ∈ 𝐻 ↔ 𝐺 ≠ (𝑉 × { 0 })))
Theorem	lkrshpor 35245	The kernel of a functional is either a hyperplane or the full vector space. (Contributed by NM, 7-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐾‘𝐺) ∈ 𝐻 ∨ (𝐾‘𝐺) = 𝑉))
Theorem	lkrshp4 35246	A kernel is a hyperplane iff it doesn't contain all vectors. (Contributed by NM, 1-Nov-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐾‘𝐺) ≠ 𝑉 ↔ (𝐾‘𝐺) ∈ 𝐻))
Theorem	lshpsmreu 35247*	Lemma for lshpkrex 35256. Show uniqueness of ring multiplier 𝑘 when a vector 𝑋 is broken down into components, one in a hyperplane and the other outside of it . TODO: do we need the cbvrexv 3367 for 𝑎 to 𝑐? (Contributed by NM, 4-Jan-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    ⇒   ⊢ (𝜑 → ∃!𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑋 = (𝑦 + (𝑘 · 𝑍)))
Theorem	lshpkrlem1 35248*	Lemma for lshpkrex 35256. The value of tentative functional 𝐺 is zero iff its argument belongs to hyperplane 𝑈. (Contributed by NM, 14-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    ⇒   ⊢ (𝜑 → (𝑋 ∈ 𝑈 ↔ (𝐺‘𝑋) = 0 ))
Theorem	lshpkrlem2 35249*	Lemma for lshpkrex 35256. The value of tentative functional 𝐺 is a scalar. (Contributed by NM, 16-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    ⇒   ⊢ (𝜑 → (𝐺‘𝑋) ∈ 𝐾)
Theorem	lshpkrlem3 35250*	Lemma for lshpkrex 35256. Defining property of 𝐺‘𝑋. (Contributed by NM, 15-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    ⇒   ⊢ (𝜑 → ∃𝑧 ∈ 𝑈 𝑋 = (𝑧 + ((𝐺‘𝑋) · 𝑍)))
Theorem	lshpkrlem4 35251*	Lemma for lshpkrex 35256. Part of showing linearity of 𝐺. (Contributed by NM, 16-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    ⇒   ⊢ (((𝜑 ∧ 𝑙 ∈ 𝐾 ∧ 𝑢 ∈ 𝑉) ∧ (𝑣 ∈ 𝑉 ∧ 𝑟 ∈ 𝑉 ∧ 𝑠 ∈ 𝑉) ∧ (𝑢 = (𝑟 + ((𝐺‘𝑢) · 𝑍)) ∧ 𝑣 = (𝑠 + ((𝐺‘𝑣) · 𝑍)))) → ((𝑙 · 𝑢) + 𝑣) = (((𝑙 · 𝑟) + 𝑠) + (((𝑙(.r‘𝐷)(𝐺‘𝑢))(+g‘𝐷)(𝐺‘𝑣)) · 𝑍)))
Theorem	lshpkrlem5 35252*	Lemma for lshpkrex 35256. Part of showing linearity of 𝐺. (Contributed by NM, 16-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    ⇒   ⊢ (((𝜑 ∧ 𝑙 ∈ 𝐾 ∧ 𝑢 ∈ 𝑉) ∧ (𝑣 ∈ 𝑉 ∧ 𝑟 ∈ 𝑈 ∧ (𝑠 ∈ 𝑈 ∧ 𝑧 ∈ 𝑈)) ∧ (𝑢 = (𝑟 + ((𝐺‘𝑢) · 𝑍)) ∧ 𝑣 = (𝑠 + ((𝐺‘𝑣) · 𝑍)) ∧ ((𝑙 · 𝑢) + 𝑣) = (𝑧 + ((𝐺‘((𝑙 · 𝑢) + 𝑣)) · 𝑍)))) → (𝐺‘((𝑙 · 𝑢) + 𝑣)) = ((𝑙(.r‘𝐷)(𝐺‘𝑢))(+g‘𝐷)(𝐺‘𝑣)))
Theorem	lshpkrlem6 35253*	Lemma for lshpkrex 35256. Show linearlity of 𝐺. (Contributed by NM, 17-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    ⇒   ⊢ ((𝜑 ∧ (𝑙 ∈ 𝐾 ∧ 𝑢 ∈ 𝑉 ∧ 𝑣 ∈ 𝑉)) → (𝐺‘((𝑙 · 𝑢) + 𝑣)) = ((𝑙(.r‘𝐷)(𝐺‘𝑢))(+g‘𝐷)(𝐺‘𝑣)))
Theorem	lshpkrcl 35254*	The set 𝐺 defined by hyperplane 𝑈 is a linear functional. (Contributed by NM, 17-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    &   ⊢ 𝐹 = (LFnl‘𝑊)    ⇒   ⊢ (𝜑 → 𝐺 ∈ 𝐹)
Theorem	lshpkr 35255*	The kernel of functional 𝐺 is the hyperplane defining it. (Contributed by NM, 17-Jul-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑊)    &   ⊢ 𝑁 = (LSpan‘𝑊)    &   ⊢ ⊕ = (LSSum‘𝑊)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝑈 ∈ 𝐻)    &   ⊢ (𝜑 → 𝑍 ∈ 𝑉)    &   ⊢ (𝜑 → (𝑈 ⊕ (𝑁‘{𝑍})) = 𝑉)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝑊)    &   ⊢ 𝐺 = (𝑥 ∈ 𝑉 ↦ (℩𝑘 ∈ 𝐾 ∃𝑦 ∈ 𝑈 𝑥 = (𝑦 + (𝑘 · 𝑍))))    &   ⊢ 𝐿 = (LKer‘𝑊)    ⇒   ⊢ (𝜑 → (𝐿‘𝐺) = 𝑈)
Theorem	lshpkrex 35256*	There exists a functional whose kernel equals a given hyperplane. Part of Th. 1.27 of Barbu and Precupanu, Convexity and Optimization in Banach Spaces. (Contributed by NM, 17-Jul-2014.)
⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ ((𝑊 ∈ LVec ∧ 𝑈 ∈ 𝐻) → ∃𝑔 ∈ 𝐹 (𝐾‘𝑔) = 𝑈)
Theorem	lshpset2N 35257*	The set of all hyperplanes of a left module or left vector space equals the set of all kernels of nonzero functionals. (Contributed by NM, 17-Jul-2014.) (New usage is discouraged.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ (𝑊 ∈ LVec → 𝐻 = {𝑠 ∣ ∃𝑔 ∈ 𝐹 (𝑔 ≠ (𝑉 × { 0 }) ∧ 𝑠 = (𝐾‘𝑔))})
Theorem	islshpkrN 35258*	The predicate "is a hyperplane" (of a left module or left vector space). TODO: should it be 𝑈 = (𝐾‘𝑔) or (𝐾‘𝑔) = 𝑈 as in lshpkrex 35256? Both standards seem to be used randomly throughout set.mm; we should decide on a preferred one. (Contributed by NM, 7-Oct-2014.) (New usage is discouraged.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    ⇒   ⊢ (𝑊 ∈ LVec → (𝑈 ∈ 𝐻 ↔ ∃𝑔 ∈ 𝐹 (𝑔 ≠ (𝑉 × { 0 }) ∧ 𝑈 = (𝐾‘𝑔))))
Theorem	lfl1dim 35259*	Equivalent expressions for a 1-dim subspace (ray) of functionals. (Contributed by NM, 24-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐿 = (LKer‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → {𝑔 ∈ 𝐹 ∣ (𝐿‘𝐺) ⊆ (𝐿‘𝑔)} = {𝑔 ∣ ∃𝑘 ∈ 𝐾 𝑔 = (𝐺 ∘𝑓 · (𝑉 × {𝑘}))})
Theorem	lfl1dim2N 35260*	Equivalent expressions for a 1-dim subspace (ray) of functionals. TODO: delete this if not useful; lfl1dim 35259 may be more compatible with lspsn 19397. (Contributed by NM, 24-Oct-2014.) (New usage is discouraged.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐷 = (Scalar‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐿 = (LKer‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐷)    &   ⊢ · = (.r‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → {𝑔 ∈ 𝐹 ∣ (𝐿‘𝐺) ⊆ (𝐿‘𝑔)} = {𝑔 ∈ 𝐹 ∣ ∃𝑘 ∈ 𝐾 𝑔 = (𝐺 ∘𝑓 · (𝑉 × {𝑘}))})
20.23.8  Opposite rings and dual vector spaces
Syntax	cld 35261	Extend class notation with left dualvector space.
class LDual
Definition	df-ldual 35262*	Define the (left) dual of a left vector space (or module) in which the vectors are functionals. In many texts, this is defined as a right vector space, but by reversing the multiplication we achieve a left vector space, as is done in definition of dual vector space in [Holland95] p. 218. This allows us to reuse our existing collection of left vector space theorems. The restriction on ∘𝑓 (+g‘𝑣) allows it to be a set; see ofmres 7441. Note the operation reversal in the scalar product to allow us to use the original scalar ring instead of the oppr ring, for convenience. (Contributed by NM, 18-Oct-2014.)
⊢ LDual = (𝑣 ∈ V ↦ ({⟨(Base‘ndx), (LFnl‘𝑣)⟩, ⟨(+g‘ndx), ( ∘𝑓 (+g‘(Scalar‘𝑣)) ↾ ((LFnl‘𝑣) × (LFnl‘𝑣)))⟩, ⟨(Scalar‘ndx), (oppr‘(Scalar‘𝑣))⟩} ∪ {⟨( ·𝑠 ‘ndx), (𝑘 ∈ (Base‘(Scalar‘𝑣)), 𝑓 ∈ (LFnl‘𝑣) ↦ (𝑓 ∘𝑓 (.r‘(Scalar‘𝑣))((Base‘𝑣) × {𝑘})))⟩}))
Theorem	ldualset 35263*	Define the (left) dual of a left vector space (or module) in which the vectors are functionals. In many texts, this is defined as a right vector space, but by reversing the multiplication we achieve a left vector space, as is done in definition of dual vector space in [Holland95] p. 218. This allows us to reuse our existing collection of left vector space theorems. Note the operation reversal in the scalar product to allow us to use the original scalar ring instead of the oppr ring, for convenience. (Contributed by NM, 18-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ ✚ = ( ∘𝑓 + ↾ (𝐹 × 𝐹))    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ · = (.r‘𝑅)    &   ⊢ 𝑂 = (oppr‘𝑅)    &   ⊢ ∙ = (𝑘 ∈ 𝐾, 𝑓 ∈ 𝐹 ↦ (𝑓 ∘𝑓 · (𝑉 × {𝑘})))    &   ⊢ (𝜑 → 𝑊 ∈ 𝑋)    ⇒   ⊢ (𝜑 → 𝐷 = ({⟨(Base‘ndx), 𝐹⟩, ⟨(+g‘ndx), ✚ ⟩, ⟨(Scalar‘ndx), 𝑂⟩} ∪ {⟨( ·𝑠 ‘ndx), ∙ ⟩}))
Theorem	ldualvbase 35264	The vectors of a dual space are functionals of the original space. (Contributed by NM, 18-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑉 = (Base‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑋)    ⇒   ⊢ (𝜑 → 𝑉 = 𝐹)
Theorem	ldualelvbase 35265	Utility theorem for converting a functional to a vector of the dual space in order to use standard vector theorems. (Contributed by NM, 6-Jan-2015.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑉 = (Base‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑋)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → 𝐺 ∈ 𝑉)
Theorem	ldualfvadd 35266	Vector addition in the dual of a vector space. (Contributed by NM, 21-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ✚ = (+g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑋)    &   ⊢ ⨣ = ( ∘𝑓 + ↾ (𝐹 × 𝐹))    ⇒   ⊢ (𝜑 → ✚ = ⨣ )
Theorem	ldualvadd 35267	Vector addition in the dual of a vector space. (Contributed by NM, 21-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ✚ = (+g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑋)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 ✚ 𝐻) = (𝐺 ∘𝑓 + 𝐻))
Theorem	ldualvaddcl 35268	The value of vector addition in the dual of a vector space is a functional. (Contributed by NM, 21-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ + = (+g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 + 𝐻) ∈ 𝐹)
Theorem	ldualvaddval 35269	The value of the value of vector addition in the dual of a vector space. (Contributed by NM, 7-Jan-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ✚ = (+g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    ⇒   ⊢ (𝜑 → ((𝐺 ✚ 𝐻)‘𝑋) = ((𝐺‘𝑋) + (𝐻‘𝑋)))
Theorem	ldualsca 35270	The ring of scalars of the dual of a vector space. (Contributed by NM, 18-Oct-2014.)
⊢ 𝐹 = (Scalar‘𝑊)    &   ⊢ 𝑂 = (oppr‘𝐹)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑋)    ⇒   ⊢ (𝜑 → 𝑅 = 𝑂)
Theorem	ldualsbase 35271	Base set of scalar ring for the dual of a vector space. (Contributed by NM, 24-Oct-2014.)
⊢ 𝐹 = (Scalar‘𝑊)    &   ⊢ 𝐿 = (Base‘𝐹)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝐷)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑉)    ⇒   ⊢ (𝜑 → 𝐾 = 𝐿)
Theorem	ldualsaddN 35272	Scalar addition for the dual of a vector space. (Contributed by NM, 24-Oct-2014.) (New usage is discouraged.)
⊢ 𝐹 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝐹)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝐷)    &   ⊢ ✚ = (+g‘𝑅)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑉)    ⇒   ⊢ (𝜑 → ✚ = + )
Theorem	ldualsmul 35273	Scalar multiplication for the dual of a vector space. (Contributed by NM, 19-Oct-2014.) (Revised by Mario Carneiro, 22-Sep-2015.)
⊢ 𝐹 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝐹)    &   ⊢ · = (.r‘𝐹)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝐷)    &   ⊢ ∙ = (.r‘𝑅)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑉)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    ⇒   ⊢ (𝜑 → (𝑋 ∙ 𝑌) = (𝑌 · 𝑋))
Theorem	ldualfvs 35274*	Scalar product operation for the dual of a vector space. (Contributed by NM, 18-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ × = (.r‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ∙ = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑌)    &   ⊢ · = (𝑘 ∈ 𝐾, 𝑓 ∈ 𝐹 ↦ (𝑓 ∘𝑓 × (𝑉 × {𝑘})))    ⇒   ⊢ (𝜑 → ∙ = · )
Theorem	ldualvs 35275	Scalar product operation value (which is a functional) for the dual of a vector space. (Contributed by NM, 18-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ × = (.r‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ∙ = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑌)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝑋 ∙ 𝐺) = (𝐺 ∘𝑓 × (𝑉 × {𝑋})))
Theorem	ldualvsval 35276	Value of scalar product operation value for the dual of a vector space. (Contributed by NM, 18-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ × = (.r‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ∙ = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ 𝑌)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐴 ∈ 𝑉)    ⇒   ⊢ (𝜑 → ((𝑋 ∙ 𝐺)‘𝐴) = ((𝐺‘𝐴) × 𝑋))
Theorem	ldualvscl 35277	The scalar product operation value is a functional. (Contributed by NM, 18-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝑋 · 𝐺) ∈ 𝐹)
Theorem	ldualvaddcom 35278	Commutative law for vector (functional) addition. (Contributed by NM, 17-Jan-2015.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ + = (+g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝑋 + 𝑌) = (𝑌 + 𝑋))
Theorem	ldualvsass 35279	Associative law for scalar product operation. (Contributed by NM, 20-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ × = (.r‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝑌 × 𝑋) · 𝐺) = (𝑋 · (𝑌 · 𝐺)))
Theorem	ldualvsass2 35280	Associative law for scalar product operation, using operations from the dual space. (Contributed by NM, 20-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑄 = (Scalar‘𝐷)    &   ⊢ × = (.r‘𝑄)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝑋 × 𝑌) · 𝐺) = (𝑋 · (𝑌 · 𝐺)))
Theorem	ldualvsdi1 35281	Distributive law for scalar product operation, using operations from the dual space. (Contributed by NM, 21-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ + = (+g‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝑋 · (𝐺 + 𝐻)) = ((𝑋 · 𝐺) + (𝑋 · 𝐻)))
Theorem	ldualvsdi2 35282	Reverse distributive law for scalar product operation, using operations from the dual space. (Contributed by NM, 21-Oct-2014.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ + = (+g‘𝑅)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ ✚ = (+g‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝐾)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝑋 + 𝑌) · 𝐺) = ((𝑋 · 𝐺) ✚ (𝑌 · 𝐺)))
Theorem	ldualgrplem 35283	Lemma for ldualgrp 35284. (Contributed by NM, 22-Oct-2014.)
⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = ∘𝑓 (+g‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ × = (.r‘𝑅)    &   ⊢ 𝑂 = (oppr‘𝑅)    &   ⊢ · = ( ·𝑠 ‘𝐷)    ⇒   ⊢ (𝜑 → 𝐷 ∈ Grp)
Theorem	ldualgrp 35284	The dual of a vector space is a group. (Contributed by NM, 21-Oct-2014.)
⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 𝐷 ∈ Grp)
Theorem	ldual0 35285	The zero scalar of the dual of a vector space. (Contributed by NM, 28-Dec-2014.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑆 = (Scalar‘𝐷)    &   ⊢ 𝑂 = (0g‘𝑆)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 𝑂 = 0 )
Theorem	ldual1 35286	The unit scalar of the dual of a vector space. (Contributed by NM, 26-Feb-2015.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 1 = (1r‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑆 = (Scalar‘𝐷)    &   ⊢ 𝐼 = (1r‘𝑆)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 𝐼 = 1 )
Theorem	ldualneg 35287	The negative of a scalar of the dual of a vector space. (Contributed by NM, 26-Feb-2015.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝑀 = (invg‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑆 = (Scalar‘𝐷)    &   ⊢ 𝑁 = (invg‘𝑆)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 𝑁 = 𝑀)
Theorem	ldual0v 35288	The zero vector of the dual of a vector space. (Contributed by NM, 24-Oct-2014.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 𝑂 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 𝑂 = (𝑉 × { 0 }))
Theorem	ldual0vcl 35289	The dual zero vector is a functional. (Contributed by NM, 5-Mar-2015.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 0 ∈ 𝐹)
Theorem	lduallmodlem 35290	Lemma for lduallmod 35291. (Contributed by NM, 22-Oct-2014.)
⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ 𝑉 = (Base‘𝑊)    &   ⊢ + = ∘𝑓 (+g‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ × = (.r‘𝑅)    &   ⊢ 𝑂 = (oppr‘𝑅)    &   ⊢ · = ( ·𝑠 ‘𝐷)    ⇒   ⊢ (𝜑 → 𝐷 ∈ LMod)
Theorem	lduallmod 35291	The dual of a left module is also a left module. (Contributed by NM, 22-Oct-2014.)
⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    ⇒   ⊢ (𝜑 → 𝐷 ∈ LMod)
Theorem	lduallvec 35292	The dual of a left vector space is also a left vector space. Note that scalar multiplication is reversed by df-oppr 19010; otherwise, the dual would be a right vector space as is sometimes the case in the literature. (Contributed by NM, 22-Oct-2014.)
⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    ⇒   ⊢ (𝜑 → 𝐷 ∈ LVec)
Theorem	ldualvsub 35293	The value of vector subtraction in the dual of a vector space. (Contributed by NM, 27-Feb-2015.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝑁 = (invg‘𝑅)    &   ⊢ 1 = (1r‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ + = (+g‘𝐷)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ − = (-g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 − 𝐻) = (𝐺 + ((𝑁‘ 1 ) · 𝐻)))
Theorem	ldualvsubcl 35294	Closure of vector subtraction in the dual of a vector space. (Contributed by NM, 27-Feb-2015.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ − = (-g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    ⇒   ⊢ (𝜑 → (𝐺 − 𝐻) ∈ 𝐹)
Theorem	ldualvsubval 35295	The value of the value of vector subtraction in the dual of a vector space. TODO: shorten with ldualvsub 35293? (Requires 𝐷 to oppr conversion.) (Contributed by NM, 26-Feb-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝑆 = (-g‘𝑅)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ − = (-g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    &   ⊢ (𝜑 → 𝐻 ∈ 𝐹)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    ⇒   ⊢ (𝜑 → ((𝐺 − 𝐻)‘𝑋) = ((𝐺‘𝑋)𝑆(𝐻‘𝑋)))
Theorem	ldualssvscl 35296	Closure of scalar product in a dual subspace.) (Contributed by NM, 5-Feb-2015.)
⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 𝐾 = (Base‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ 𝑆 = (LSubSp‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑈 ∈ 𝑆)    &   ⊢ (𝜑 → 𝑋 ∈ 𝐾)    &   ⊢ (𝜑 → 𝑌 ∈ 𝑈)    ⇒   ⊢ (𝜑 → (𝑋 · 𝑌) ∈ 𝑈)
Theorem	ldualssvsubcl 35297	Closure of vector subtraction in a dual subspace.) (Contributed by NM, 9-Mar-2015.)
⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ − = (-g‘𝐷)    &   ⊢ 𝑆 = (LSubSp‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝑈 ∈ 𝑆)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑈)    &   ⊢ (𝜑 → 𝑌 ∈ 𝑈)    ⇒   ⊢ (𝜑 → (𝑋 − 𝑌) ∈ 𝑈)
Theorem	ldual0vs 35298	Scalar zero times a functional is the zero functional. (Contributed by NM, 17-Feb-2015.)
⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝑅 = (Scalar‘𝑊)    &   ⊢ 0 = (0g‘𝑅)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ · = ( ·𝑠 ‘𝐷)    &   ⊢ 𝑂 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ( 0 · 𝐺) = 𝑂)
Theorem	lkr0f2 35299	The kernel of the zero functional is the set of all vectors. (Contributed by NM, 4-Feb-2015.)
⊢ 𝑉 = (Base‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LMod)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐾‘𝐺) = 𝑉 ↔ 𝐺 = 0 ))
Theorem	lduallkr3 35300	The kernels of nonzero functionals are hyperplanes. (Contributed by NM, 22-Feb-2015.)
⊢ 𝐻 = (LSHyp‘𝑊)    &   ⊢ 𝐹 = (LFnl‘𝑊)    &   ⊢ 𝐾 = (LKer‘𝑊)    &   ⊢ 𝐷 = (LDual‘𝑊)    &   ⊢ 0 = (0g‘𝐷)    &   ⊢ (𝜑 → 𝑊 ∈ LVec)    &   ⊢ (𝜑 → 𝐺 ∈ 𝐹)    ⇒   ⊢ (𝜑 → ((𝐾‘𝐺) ∈ 𝐻 ↔ 𝐺 ≠ 0 ))