P. 359 of Theorem List - Metamath Proof Explorer

Theorem List for Metamath Proof Explorer - 35801-35900   *Has distinct variable group(s)

Type	Label	Description
Statement
Definition	df-mpps 35801*	Define the set of provable pre-statements. (Contributed by Mario Carneiro, 14-Jul-2016.)
⊢ mPPSt = (𝑡 ∈ V ↦ {⟨⟨𝑑, ℎ⟩, 𝑎⟩ ∣ (⟨𝑑, ℎ, 𝑎⟩ ∈ (mPreSt‘𝑡) ∧ 𝑎 ∈ (𝑑(mCls‘𝑡)ℎ))})
Definition	df-mthm 35802	Define the set of theorems. (Contributed by Mario Carneiro, 14-Jul-2016.)
⊢ mThm = (𝑡 ∈ V ↦ (◡(mStRed‘𝑡) “ ((mStRed‘𝑡) “ (mPPSt‘𝑡))))
Theorem	mvtval 35803	The set of variable typecodes. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVT‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    ⇒   ⊢ 𝑉 = ran 𝑌
Theorem	mrexval 35804	The set of "raw expressions", which are expressions without a typecode, that is, just sequences of constants and variables. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → 𝑅 = Word (𝐶 ∪ 𝑉))
Theorem	mexval 35805	The set of expressions, which are pairs whose first element is a typecode, and whose second element is a raw expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐾 = (mTC‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    ⇒   ⊢ 𝐸 = (𝐾 × 𝑅)
Theorem	mexval2 35806	The set of expressions, which are pairs whose first element is a typecode, and whose second element is a list of constants and variables. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐾 = (mTC‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    ⇒   ⊢ 𝐸 = (𝐾 × Word (𝐶 ∪ 𝑉))
Theorem	mdvval 35807	The set of disjoint variable conditions, which are pairs of distinct variables. (This definition differs from appendix C, which uses unordered pairs instead. We use ordered pairs, but all sets of disjoint variable conditions of interest will be symmetric, so it does not matter.) (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐷 = (mDV‘𝑇)    ⇒   ⊢ 𝐷 = ((𝑉 × 𝑉) ∖ I )
Theorem	mvrsval 35808	The set of variables in an expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑊 = (mVars‘𝑇)    ⇒   ⊢ (𝑋 ∈ 𝐸 → (𝑊‘𝑋) = (ran (2nd ‘𝑋) ∩ 𝑉))
Theorem	mvrsfpw 35809	The set of variables in an expression is a finite subset of 𝑉. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑊 = (mVars‘𝑇)    ⇒   ⊢ (𝑋 ∈ 𝐸 → (𝑊‘𝑋) ∈ (𝒫 𝑉 ∩ Fin))
Theorem	mrsubffval 35810*	The substitution of some variables for expressions in a raw expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝐺 = (freeMnd‘(𝐶 ∪ 𝑉))    ⇒   ⊢ (𝑇 ∈ 𝑊 → 𝑆 = (𝑓 ∈ (𝑅 ↑pm 𝑉) ↦ (𝑒 ∈ 𝑅 ↦ (𝐺 Σg ((𝑣 ∈ (𝐶 ∪ 𝑉) ↦ if(𝑣 ∈ dom 𝑓, (𝑓‘𝑣), ⟨“𝑣”⟩)) ∘ 𝑒)))))
Theorem	mrsubfval 35811*	The substitution of some variables for expressions in a raw expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝐺 = (freeMnd‘(𝐶 ∪ 𝑉))    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉) → (𝑆‘𝐹) = (𝑒 ∈ 𝑅 ↦ (𝐺 Σg ((𝑣 ∈ (𝐶 ∪ 𝑉) ↦ if(𝑣 ∈ 𝐴, (𝐹‘𝑣), ⟨“𝑣”⟩)) ∘ 𝑒))))
Theorem	mrsubval 35812*	The substitution of some variables for expressions in a raw expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝐺 = (freeMnd‘(𝐶 ∪ 𝑉))    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉 ∧ 𝑋 ∈ 𝑅) → ((𝑆‘𝐹)‘𝑋) = (𝐺 Σg ((𝑣 ∈ (𝐶 ∪ 𝑉) ↦ if(𝑣 ∈ 𝐴, (𝐹‘𝑣), ⟨“𝑣”⟩)) ∘ 𝑋)))
Theorem	mrsubcv 35813	The value of a substituted singleton. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉 ∧ 𝑋 ∈ (𝐶 ∪ 𝑉)) → ((𝑆‘𝐹)‘⟨“𝑋”⟩) = if(𝑋 ∈ 𝐴, (𝐹‘𝑋), ⟨“𝑋”⟩))
Theorem	mrsubvr 35814	The value of a substituted variable. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉 ∧ 𝑋 ∈ 𝐴) → ((𝑆‘𝐹)‘⟨“𝑋”⟩) = (𝐹‘𝑋))
Theorem	mrsubff 35815	A substitution is a function from 𝑅 to 𝑅. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → 𝑆:(𝑅 ↑pm 𝑉)⟶(𝑅 ↑m 𝑅))
Theorem	mrsubrn 35816	Although it is defined for partial mappings of variables, every partial substitution is a substitution on some complete mapping of the variables. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ ran 𝑆 = (𝑆 “ (𝑅 ↑m 𝑉))
Theorem	mrsubff1 35817	When restricted to complete mappings, the substitution-producing function is one-to-one. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → (𝑆 ↾ (𝑅 ↑m 𝑉)):(𝑅 ↑m 𝑉)–1-1→(𝑅 ↑m 𝑅))
Theorem	mrsubff1o 35818	When restricted to complete mappings, the substitution-producing function is bijective to the set of all substitutions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → (𝑆 ↾ (𝑅 ↑m 𝑉)):(𝑅 ↑m 𝑉)–1-1-onto→ran 𝑆)
Theorem	mrsub0 35819	The value of the substituted empty string. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ (𝐹 ∈ ran 𝑆 → (𝐹‘∅) = ∅)
Theorem	mrsubf 35820	A substitution is a function. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    ⇒   ⊢ (𝐹 ∈ ran 𝑆 → 𝐹:𝑅⟶𝑅)
Theorem	mrsubccat 35821	Substitution distributes over concatenation. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    ⇒   ⊢ ((𝐹 ∈ ran 𝑆 ∧ 𝑋 ∈ 𝑅 ∧ 𝑌 ∈ 𝑅) → (𝐹‘(𝑋 ++ 𝑌)) = ((𝐹‘𝑋) ++ (𝐹‘𝑌)))
Theorem	mrsubcn 35822	A substitution does not change the value of constant substrings. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐶 = (mCN‘𝑇)    ⇒   ⊢ ((𝐹 ∈ ran 𝑆 ∧ 𝑋 ∈ (𝐶 ∖ 𝑉)) → (𝐹‘⟨“𝑋”⟩) = ⟨“𝑋”⟩)
Theorem	elmrsubrn 35823*	Characterization of the substitutions as functions from expressions to expressions that distribute under concatenation and map constants to themselves. (The constant part uses (𝐶 ∖ 𝑉) because we don't know that 𝐶 and 𝑉 are disjoint until we get to ismfs 35852.) (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐶 = (mCN‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → (𝐹 ∈ ran 𝑆 ↔ (𝐹:𝑅⟶𝑅 ∧ ∀𝑐 ∈ (𝐶 ∖ 𝑉)(𝐹‘⟨“𝑐”⟩) = ⟨“𝑐”⟩ ∧ ∀𝑥 ∈ 𝑅 ∀𝑦 ∈ 𝑅 (𝐹‘(𝑥 ++ 𝑦)) = ((𝐹‘𝑥) ++ (𝐹‘𝑦)))))
Theorem	mrsubco 35824	The composition of two substitutions is a substitution. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    ⇒   ⊢ ((𝐹 ∈ ran 𝑆 ∧ 𝐺 ∈ ran 𝑆) → (𝐹 ∘ 𝐺) ∈ ran 𝑆)
Theorem	mrsubvrs 35825*	The set of variables in a substitution is the union, indexed by the variables in the original expression, of the variables in the substitution to that variable. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mRSubst‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    ⇒   ⊢ ((𝐹 ∈ ran 𝑆 ∧ 𝑋 ∈ 𝑅) → (ran (𝐹‘𝑋) ∩ 𝑉) = ∪ 𝑥 ∈ (ran 𝑋 ∩ 𝑉)(ran (𝐹‘⟨“𝑥”⟩) ∩ 𝑉))
Theorem	msubffval 35826*	A substitution applied to an expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑂 = (mRSubst‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → 𝑆 = (𝑓 ∈ (𝑅 ↑pm 𝑉) ↦ (𝑒 ∈ 𝐸 ↦ ⟨(1st ‘𝑒), ((𝑂‘𝑓)‘(2nd ‘𝑒))⟩)))
Theorem	msubfval 35827*	A substitution applied to an expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑂 = (mRSubst‘𝑇)    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉) → (𝑆‘𝐹) = (𝑒 ∈ 𝐸 ↦ ⟨(1st ‘𝑒), ((𝑂‘𝐹)‘(2nd ‘𝑒))⟩))
Theorem	msubval 35828	A substitution applied to an expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑂 = (mRSubst‘𝑇)    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉 ∧ 𝑋 ∈ 𝐸) → ((𝑆‘𝐹)‘𝑋) = ⟨(1st ‘𝑋), ((𝑂‘𝐹)‘(2nd ‘𝑋))⟩)
Theorem	msubrsub 35829	A substitution applied to an expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑂 = (mRSubst‘𝑇)    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉 ∧ 𝑋 ∈ 𝐸) → (2nd ‘((𝑆‘𝐹)‘𝑋)) = ((𝑂‘𝐹)‘(2nd ‘𝑋)))
Theorem	msubty 35830	The type of a substituted expression is the same as the original type. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    ⇒   ⊢ ((𝐹:𝐴⟶𝑅 ∧ 𝐴 ⊆ 𝑉 ∧ 𝑋 ∈ 𝐸) → (1st ‘((𝑆‘𝐹)‘𝑋)) = (1st ‘𝑋))
Theorem	elmsubrn 35831*	Characterization of substitution in terms of raw substitution, without reference to the generating functions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑂 = (mRSubst‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    ⇒   ⊢ ran 𝑆 = ran (𝑓 ∈ ran 𝑂 ↦ (𝑒 ∈ 𝐸 ↦ ⟨(1st ‘𝑒), (𝑓‘(2nd ‘𝑒))⟩))
Theorem	msubrn 35832	Although it is defined for partial mappings of variables, every partial substitution is a substitution on some complete mapping of the variables. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    ⇒   ⊢ ran 𝑆 = (𝑆 “ (𝑅 ↑m 𝑉))
Theorem	msubff 35833	A substitution is a function from 𝐸 to 𝐸. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → 𝑆:(𝑅 ↑pm 𝑉)⟶(𝐸 ↑m 𝐸))
Theorem	msubco 35834	The composition of two substitutions is a substitution. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mSubst‘𝑇)    ⇒   ⊢ ((𝐹 ∈ ran 𝑆 ∧ 𝐺 ∈ ran 𝑆) → (𝐹 ∘ 𝐺) ∈ ran 𝑆)
Theorem	msubf 35835	A substitution is a function. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    ⇒   ⊢ (𝐹 ∈ ran 𝑆 → 𝐹:𝐸⟶𝐸)
Theorem	mvhfval 35836*	Value of the function mapping variables to their corresponding variable expressions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    ⇒   ⊢ 𝐻 = (𝑣 ∈ 𝑉 ↦ ⟨(𝑌‘𝑣), ⟨“𝑣”⟩⟩)
Theorem	mvhval 35837	Value of the function mapping variables to their corresponding variable expressions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    ⇒   ⊢ (𝑋 ∈ 𝑉 → (𝐻‘𝑋) = ⟨(𝑌‘𝑋), ⟨“𝑋”⟩⟩)
Theorem	mpstval 35838*	A pre-statement is an ordered triple, whose first member is a symmetric set of disjoint variable conditions, whose second member is a finite set of expressions, and whose third member is an expression. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑃 = (mPreSt‘𝑇)    ⇒   ⊢ 𝑃 = (({𝑑 ∈ 𝒫 𝑉 ∣ ◡𝑑 = 𝑑} × (𝒫 𝐸 ∩ Fin)) × 𝐸)
Theorem	elmpst 35839	Property of being a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑃 = (mPreSt‘𝑇)    ⇒   ⊢ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝑃 ↔ ((𝐷 ⊆ 𝑉 ∧ ◡𝐷 = 𝐷) ∧ (𝐻 ⊆ 𝐸 ∧ 𝐻 ∈ Fin) ∧ 𝐴 ∈ 𝐸))
Theorem	msrfval 35840*	Value of the reduct of a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVars‘𝑇)    &   ⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝑅 = (mStRed‘𝑇)    ⇒   ⊢ 𝑅 = (𝑠 ∈ 𝑃 ↦ ⦋(2nd ‘(1st ‘𝑠)) / ℎ⦌⦋(2nd ‘𝑠) / 𝑎⦌⟨((1st ‘(1st ‘𝑠)) ∩ ⦋∪ (𝑉 “ (ℎ ∪ {𝑎})) / 𝑧⦌(𝑧 × 𝑧)), ℎ, 𝑎⟩)
Theorem	msrval 35841	Value of the reduct of a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVars‘𝑇)    &   ⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝑍 = ∪ (𝑉 “ (𝐻 ∪ {𝐴}))    ⇒   ⊢ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝑃 → (𝑅‘⟨𝐷, 𝐻, 𝐴⟩) = ⟨(𝐷 ∩ (𝑍 × 𝑍)), 𝐻, 𝐴⟩)
Theorem	mpstssv 35842	A pre-statement is an ordered triple. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    ⇒   ⊢ 𝑃 ⊆ ((V × V) × V)
Theorem	mpst123 35843	Decompose a pre-statement into a triple of values. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    ⇒   ⊢ (𝑋 ∈ 𝑃 → 𝑋 = ⟨(1st ‘(1st ‘𝑋)), (2nd ‘(1st ‘𝑋)), (2nd ‘𝑋)⟩)
Theorem	mpstrcl 35844	The elements of a pre-statement are sets. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    ⇒   ⊢ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝑃 → (𝐷 ∈ V ∧ 𝐻 ∈ V ∧ 𝐴 ∈ V))
Theorem	msrf 35845	The reduct of a pre-statement is a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝑅 = (mStRed‘𝑇)    ⇒   ⊢ 𝑅:𝑃⟶𝑃
Theorem	msrrcl 35846	If 𝑋 and 𝑌 have the same reduct, then one is a pre-statement iff the other is. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝑅 = (mStRed‘𝑇)    ⇒   ⊢ ((𝑅‘𝑋) = (𝑅‘𝑌) → (𝑋 ∈ 𝑃 ↔ 𝑌 ∈ 𝑃))
Theorem	mstaval 35847	Value of the set of statements. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    ⇒   ⊢ 𝑆 = ran 𝑅
Theorem	msrid 35848	The reduct of a statement is itself. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    ⇒   ⊢ (𝑋 ∈ 𝑆 → (𝑅‘𝑋) = 𝑋)
Theorem	msrfo 35849	The reduct of a pre-statement is a statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    &   ⊢ 𝑃 = (mPreSt‘𝑇)    ⇒   ⊢ 𝑅:𝑃–onto→𝑆
Theorem	mstapst 35850	A statement is a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    ⇒   ⊢ 𝑆 ⊆ 𝑃
Theorem	elmsta 35851	Property of being a statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    &   ⊢ 𝑉 = (mVars‘𝑇)    &   ⊢ 𝑍 = ∪ (𝑉 “ (𝐻 ∪ {𝐴}))    ⇒   ⊢ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝑆 ↔ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝑃 ∧ 𝐷 ⊆ (𝑍 × 𝑍)))
Theorem	ismfs 35852*	A formal system is a tuple ⟨mCN, mVR, mType, mVT, mTC, mAx⟩ such that: mCN and mVR are disjoint; mType is a function from mVR to mVT; mVT is a subset of mTC; mAx is a set of statements; and for each variable typecode, there are infinitely many variables of that type. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    &   ⊢ 𝐹 = (mVT‘𝑇)    &   ⊢ 𝐾 = (mTC‘𝑇)    &   ⊢ 𝐴 = (mAx‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    ⇒   ⊢ (𝑇 ∈ 𝑊 → (𝑇 ∈ mFS ↔ (((𝐶 ∩ 𝑉) = ∅ ∧ 𝑌:𝑉⟶𝐾) ∧ (𝐴 ⊆ 𝑆 ∧ ∀𝑣 ∈ 𝐹 ¬ (◡𝑌 “ {𝑣}) ∈ Fin))))
Theorem	mfsdisj 35853	The constants and variables of a formal system are disjoint. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐶 = (mCN‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → (𝐶 ∩ 𝑉) = ∅)
Theorem	mtyf2 35854	The type function maps variables to typecodes. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐾 = (mTC‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → 𝑌:𝑉⟶𝐾)
Theorem	mtyf 35855	The type function maps variables to variable typecodes. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐹 = (mVT‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → 𝑌:𝑉⟶𝐹)
Theorem	mvtss 35856	The set of variable typecodes is a subset of all typecodes. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐹 = (mVT‘𝑇)    &   ⊢ 𝐾 = (mTC‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → 𝐹 ⊆ 𝐾)
Theorem	maxsta 35857	An axiom is a statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐴 = (mAx‘𝑇)    &   ⊢ 𝑆 = (mStat‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → 𝐴 ⊆ 𝑆)
Theorem	mvtinf 35858	Each variable typecode has infinitely many variables. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐹 = (mVT‘𝑇)    &   ⊢ 𝑌 = (mType‘𝑇)    ⇒   ⊢ ((𝑇 ∈ mFS ∧ 𝑋 ∈ 𝐹) → ¬ (◡𝑌 “ {𝑋}) ∈ Fin)
Theorem	msubff1 35859	When restricted to complete mappings, the substitution-producing function is one-to-one. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → (𝑆 ↾ (𝑅 ↑m 𝑉)):(𝑅 ↑m 𝑉)–1-1→(𝐸 ↑m 𝐸))
Theorem	msubff1o 35860	When restricted to complete mappings, the substitution-producing function is bijective to the set of all substitutions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝑅 = (mREx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → (𝑆 ↾ (𝑅 ↑m 𝑉)):(𝑅 ↑m 𝑉)–1-1-onto→ran 𝑆)
Theorem	mvhf 35861	The function mapping variables to variable expressions is a function. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → 𝐻:𝑉⟶𝐸)
Theorem	mvhf1 35862	The function mapping variables to variable expressions is one-to-one. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    ⇒   ⊢ (𝑇 ∈ mFS → 𝐻:𝑉–1-1→𝐸)
Theorem	msubvrs 35863*	The set of variables in a substitution is the union, indexed by the variables in the original expression, of the variables in the substitution to that variable. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝑉 = (mVars‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    ⇒   ⊢ ((𝑇 ∈ mFS ∧ 𝐹 ∈ ran 𝑆 ∧ 𝑋 ∈ 𝐸) → (𝑉‘(𝐹‘𝑋)) = ∪ 𝑥 ∈ (𝑉‘𝑋)(𝑉‘(𝐹‘(𝐻‘𝑥))))
Theorem	mclsrcl 35864	Reverse closure for the closure function. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    ⇒   ⊢ (𝐴 ∈ (𝐾𝐶𝐵) → (𝑇 ∈ V ∧ 𝐾 ⊆ 𝐷 ∧ 𝐵 ⊆ 𝐸))
Theorem	mclsssvlem 35865*	Lemma for mclsssv 35867. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝐴 = (mAx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝑉 = (mVars‘𝑇)    ⇒   ⊢ (𝜑 → ∩ {𝑐 ∣ ((𝐵 ∪ ran 𝐻) ⊆ 𝑐 ∧ ∀𝑚∀𝑜∀𝑝(⟨𝑚, 𝑜, 𝑝⟩ ∈ 𝐴 → ∀𝑠 ∈ ran 𝑆(((𝑠 “ (𝑜 ∪ ran 𝐻)) ⊆ 𝑐 ∧ ∀𝑥∀𝑦(𝑥𝑚𝑦 → ((𝑉‘(𝑠‘(𝐻‘𝑥))) × (𝑉‘(𝑠‘(𝐻‘𝑦)))) ⊆ 𝐾)) → (𝑠‘𝑝) ∈ 𝑐)))} ⊆ 𝐸)
Theorem	mclsval 35866*	The function mapping variables to variable expressions is one-to-one. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝐴 = (mAx‘𝑇)    &   ⊢ 𝑆 = (mSubst‘𝑇)    &   ⊢ 𝑉 = (mVars‘𝑇)    ⇒   ⊢ (𝜑 → (𝐾𝐶𝐵) = ∩ {𝑐 ∣ ((𝐵 ∪ ran 𝐻) ⊆ 𝑐 ∧ ∀𝑚∀𝑜∀𝑝(⟨𝑚, 𝑜, 𝑝⟩ ∈ 𝐴 → ∀𝑠 ∈ ran 𝑆(((𝑠 “ (𝑜 ∪ ran 𝐻)) ⊆ 𝑐 ∧ ∀𝑥∀𝑦(𝑥𝑚𝑦 → ((𝑉‘(𝑠‘(𝐻‘𝑥))) × (𝑉‘(𝑠‘(𝐻‘𝑦)))) ⊆ 𝐾)) → (𝑠‘𝑝) ∈ 𝑐)))})
Theorem	mclsssv 35867	The closure of a set of expressions is a set of expressions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    ⇒   ⊢ (𝜑 → (𝐾𝐶𝐵) ⊆ 𝐸)
Theorem	ssmclslem 35868	Lemma for ssmcls 35870. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐻 = (mVH‘𝑇)    ⇒   ⊢ (𝜑 → (𝐵 ∪ ran 𝐻) ⊆ (𝐾𝐶𝐵))
Theorem	vhmcls 35869	All variable hypotheses are in the closure. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ (𝜑 → 𝑋 ∈ 𝑉)    ⇒   ⊢ (𝜑 → (𝐻‘𝑋) ∈ (𝐾𝐶𝐵))
Theorem	ssmcls 35870	The original expressions are also in the closure. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    ⇒   ⊢ (𝜑 → 𝐵 ⊆ (𝐾𝐶𝐵))
Theorem	ss2mcls 35871	The closure is monotonic under subsets of the original set of expressions and the set of disjoint variable conditions. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ (𝜑 → 𝑋 ⊆ 𝐾)    &   ⊢ (𝜑 → 𝑌 ⊆ 𝐵)    ⇒   ⊢ (𝜑 → (𝑋𝐶𝑌) ⊆ (𝐾𝐶𝐵))
Theorem	mclsax 35872*	The closure is closed under axiom application. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐴 = (mAx‘𝑇)    &   ⊢ 𝐿 = (mSubst‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝑊 = (mVars‘𝑇)    &   ⊢ (𝜑 → ⟨𝑀, 𝑂, 𝑃⟩ ∈ 𝐴)    &   ⊢ (𝜑 → 𝑆 ∈ ran 𝐿)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑂) → (𝑆‘𝑥) ∈ (𝐾𝐶𝐵))    &   ⊢ ((𝜑 ∧ 𝑣 ∈ 𝑉) → (𝑆‘(𝐻‘𝑣)) ∈ (𝐾𝐶𝐵))    &   ⊢ ((𝜑 ∧ (𝑥𝑀𝑦 ∧ 𝑎 ∈ (𝑊‘(𝑆‘(𝐻‘𝑥))) ∧ 𝑏 ∈ (𝑊‘(𝑆‘(𝐻‘𝑦))))) → 𝑎𝐾𝑏)    ⇒   ⊢ (𝜑 → (𝑆‘𝑃) ∈ (𝐾𝐶𝐵))
Theorem	mclsind 35873*	Induction theorem for closure: any other set 𝑄 closed under the axioms and the hypotheses contains all the elements of the closure. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐴 = (mAx‘𝑇)    &   ⊢ 𝐿 = (mSubst‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝑊 = (mVars‘𝑇)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝑄)    &   ⊢ ((𝜑 ∧ 𝑣 ∈ 𝑉) → (𝐻‘𝑣) ∈ 𝑄)    &   ⊢ ((𝜑 ∧ (⟨𝑚, 𝑜, 𝑝⟩ ∈ 𝐴 ∧ 𝑠 ∈ ran 𝐿 ∧ (𝑠 “ (𝑜 ∪ ran 𝐻)) ⊆ 𝑄) ∧ ∀𝑥∀𝑦(𝑥𝑚𝑦 → ((𝑊‘(𝑠‘(𝐻‘𝑥))) × (𝑊‘(𝑠‘(𝐻‘𝑦)))) ⊆ 𝐾)) → (𝑠‘𝑝) ∈ 𝑄)    ⇒   ⊢ (𝜑 → (𝐾𝐶𝐵) ⊆ 𝑄)
Theorem	mppspstlem 35874*	Lemma for mppspst 35877. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    ⇒   ⊢ {⟨⟨𝑑, ℎ⟩, 𝑎⟩ ∣ (⟨𝑑, ℎ, 𝑎⟩ ∈ 𝑃 ∧ 𝑎 ∈ (𝑑𝐶ℎ))} ⊆ 𝑃
Theorem	mppsval 35875*	Definition of a provable pre-statement, essentially just a reorganization of the arguments of df-mcls . (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    ⇒   ⊢ 𝐽 = {⟨⟨𝑑, ℎ⟩, 𝑎⟩ ∣ (⟨𝑑, ℎ, 𝑎⟩ ∈ 𝑃 ∧ 𝑎 ∈ (𝑑𝐶ℎ))}
Theorem	elmpps 35876	Definition of a provable pre-statement, essentially just a reorganization of the arguments of df-mcls . (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    ⇒   ⊢ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝐽 ↔ (⟨𝐷, 𝐻, 𝐴⟩ ∈ 𝑃 ∧ 𝐴 ∈ (𝐷𝐶𝐻)))
Theorem	mppspst 35877	A provable pre-statement is a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑃 = (mPreSt‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    ⇒   ⊢ 𝐽 ⊆ 𝑃
Theorem	mthmval 35878	A theorem is a pre-statement, whose reduct is also the reduct of a provable pre-statement. Unlike the difference between pre-statement and statement, this application of the reduct is not necessarily trivial: there are theorems that are not themselves provable but are provable once enough "dummy variables" are introduced. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    ⇒   ⊢ 𝑈 = (◡𝑅 “ (𝑅 “ 𝐽))
Theorem	elmthm 35879*	A theorem is a pre-statement, whose reduct is also the reduct of a provable pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    ⇒   ⊢ (𝑋 ∈ 𝑈 ↔ ∃𝑥 ∈ 𝐽 (𝑅‘𝑥) = (𝑅‘𝑋))
Theorem	mthmi 35880	A statement whose reduct is the reduct of a provable pre-statement is a theorem. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    ⇒   ⊢ ((𝑋 ∈ 𝐽 ∧ (𝑅‘𝑋) = (𝑅‘𝑌)) → 𝑌 ∈ 𝑈)
Theorem	mthmsta 35881	A theorem is a pre-statement. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑈 = (mThm‘𝑇)    &   ⊢ 𝑆 = (mPreSt‘𝑇)    ⇒   ⊢ 𝑈 ⊆ 𝑆
Theorem	mppsthm 35882	A provable pre-statement is a theorem. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    ⇒   ⊢ 𝐽 ⊆ 𝑈
Theorem	mthmblem 35883	Lemma for mthmb 35884. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    ⇒   ⊢ ((𝑅‘𝑋) = (𝑅‘𝑌) → (𝑋 ∈ 𝑈 → 𝑌 ∈ 𝑈))
Theorem	mthmb 35884	If two statements have the same reduct then one is a theorem iff the other is. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    ⇒   ⊢ ((𝑅‘𝑋) = (𝑅‘𝑌) → (𝑋 ∈ 𝑈 ↔ 𝑌 ∈ 𝑈))
Theorem	mthmpps 35885	Given a theorem, there is an explicitly definable witnessing provable pre-statement for the provability of the theorem. (However, this pre-statement requires infinitely many disjoint variable conditions, which is sometimes inconvenient.) (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝑅 = (mStRed‘𝑇)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝑈 = (mThm‘𝑇)    &   ⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝑉 = (mVars‘𝑇)    &   ⊢ 𝑍 = ∪ (𝑉 “ (𝐻 ∪ {𝐴}))    &   ⊢ 𝑀 = (𝐶 ∪ (𝐷 ∖ (𝑍 × 𝑍)))    ⇒   ⊢ (𝑇 ∈ mFS → (⟨𝐶, 𝐻, 𝐴⟩ ∈ 𝑈 ↔ (⟨𝑀, 𝐻, 𝐴⟩ ∈ 𝐽 ∧ (𝑅‘⟨𝑀, 𝐻, 𝐴⟩) = (𝑅‘⟨𝐶, 𝐻, 𝐴⟩))))
Theorem	mclsppslem 35886*	The closure is closed under application of provable pre-statements. (Compare mclsax 35872.) This theorem is what justifies the treatment of theorems as "equivalent" to axioms once they have been proven: the composition of one theorem in the proof of another yields a theorem. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝐿 = (mSubst‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝑊 = (mVars‘𝑇)    &   ⊢ (𝜑 → ⟨𝑀, 𝑂, 𝑃⟩ ∈ 𝐽)    &   ⊢ (𝜑 → 𝑆 ∈ ran 𝐿)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑂) → (𝑆‘𝑥) ∈ (𝐾𝐶𝐵))    &   ⊢ ((𝜑 ∧ 𝑣 ∈ 𝑉) → (𝑆‘(𝐻‘𝑣)) ∈ (𝐾𝐶𝐵))    &   ⊢ ((𝜑 ∧ (𝑥𝑀𝑦 ∧ 𝑎 ∈ (𝑊‘(𝑆‘(𝐻‘𝑥))) ∧ 𝑏 ∈ (𝑊‘(𝑆‘(𝐻‘𝑦))))) → 𝑎𝐾𝑏)    &   ⊢ (𝜑 → ⟨𝑚, 𝑜, 𝑝⟩ ∈ (mAx‘𝑇))    &   ⊢ (𝜑 → 𝑠 ∈ ran 𝐿)    &   ⊢ (𝜑 → (𝑠 “ (𝑜 ∪ ran 𝐻)) ⊆ (◡𝑆 “ (𝐾𝐶𝐵)))    &   ⊢ (𝜑 → ∀𝑧∀𝑤(𝑧𝑚𝑤 → ((𝑊‘(𝑠‘(𝐻‘𝑧))) × (𝑊‘(𝑠‘(𝐻‘𝑤)))) ⊆ 𝑀))    ⇒   ⊢ (𝜑 → (𝑠‘𝑝) ∈ (◡𝑆 “ (𝐾𝐶𝐵)))
Theorem	mclspps 35887*	The closure is closed under application of provable pre-statements. (Compare mclsax 35872.) This theorem is what justifies the treatment of theorems as "equivalent" to axioms once they have been proven: the composition of one theorem in the proof of another yields a theorem. (Contributed by Mario Carneiro, 18-Jul-2016.)
⊢ 𝐷 = (mDV‘𝑇)    &   ⊢ 𝐸 = (mEx‘𝑇)    &   ⊢ 𝐶 = (mCls‘𝑇)    &   ⊢ (𝜑 → 𝑇 ∈ mFS)    &   ⊢ (𝜑 → 𝐾 ⊆ 𝐷)    &   ⊢ (𝜑 → 𝐵 ⊆ 𝐸)    &   ⊢ 𝐽 = (mPPSt‘𝑇)    &   ⊢ 𝐿 = (mSubst‘𝑇)    &   ⊢ 𝑉 = (mVR‘𝑇)    &   ⊢ 𝐻 = (mVH‘𝑇)    &   ⊢ 𝑊 = (mVars‘𝑇)    &   ⊢ (𝜑 → ⟨𝑀, 𝑂, 𝑃⟩ ∈ 𝐽)    &   ⊢ (𝜑 → 𝑆 ∈ ran 𝐿)    &   ⊢ ((𝜑 ∧ 𝑥 ∈ 𝑂) → (𝑆‘𝑥) ∈ (𝐾𝐶𝐵))    &   ⊢ ((𝜑 ∧ 𝑣 ∈ 𝑉) → (𝑆‘(𝐻‘𝑣)) ∈ (𝐾𝐶𝐵))    &   ⊢ ((𝜑 ∧ (𝑥𝑀𝑦 ∧ 𝑎 ∈ (𝑊‘(𝑆‘(𝐻‘𝑥))) ∧ 𝑏 ∈ (𝑊‘(𝑆‘(𝐻‘𝑦))))) → 𝑎𝐾𝑏)    ⇒   ⊢ (𝜑 → (𝑆‘𝑃) ∈ (𝐾𝐶𝐵))
21.6.14  Grammatical formal systems
Syntax	cm0s 35888	Mapping expressions to statements.
class m0St
Syntax	cmsa 35889	The set of syntax axioms.
class mSA
Syntax	cmwgfs 35890	The set of weakly grammatical formal systems.
class mWGFS
Syntax	cmsy 35891	The syntax typecode function.
class mSyn
Syntax	cmesy 35892	The syntax typecode function for expressions.
class mESyn
Syntax	cmgfs 35893	The set of grammatical formal systems.
class mGFS
Syntax	cmtree 35894	The set of proof trees.
class mTree
Syntax	cmst 35895	The set of syntax trees.
class mST
Syntax	cmsax 35896	The indexing set for a syntax axiom.
class mSAX
Syntax	cmufs 35897	The set of unambiguous formal systems.
class mUFS
Definition	df-m0s 35898	Define a function mapping expressions to statements. (Contributed by Mario Carneiro, 14-Jul-2016.)
⊢ m0St = (𝑎 ∈ V ↦ ⟨∅, ∅, 𝑎⟩)
Definition	df-msa 35899*	Define the set of syntax axioms. (Contributed by Mario Carneiro, 14-Jul-2016.)
⊢ mSA = (𝑡 ∈ V ↦ {𝑎 ∈ (mEx‘𝑡) ∣ ((m0St‘𝑎) ∈ (mAx‘𝑡) ∧ (1st ‘𝑎) ∈ (mVT‘𝑡) ∧ Fun (◡(2nd ‘𝑎) ↾ (mVR‘𝑡)))})
Definition	df-mwgfs 35900*	Define the set of weakly grammatical formal systems. (Contributed by Mario Carneiro, 14-Jul-2016.)
⊢ mWGFS = {𝑡 ∈ mFS ∣ ∀𝑑∀ℎ∀𝑎((⟨𝑑, ℎ, 𝑎⟩ ∈ (mAx‘𝑡) ∧ (1st ‘𝑎) ∈ (mVT‘𝑡)) → ∃𝑠 ∈ ran (mSubst‘𝑡)𝑎 ∈ (𝑠 “ (mSA‘𝑡)))}