TPTP Problem File: COM132+2.p

View Solutions - Solve Problem

%------------------------------------------------------------------------------
% File     : COM132+2 : TPTP v9.0.0. Released v6.4.0.
% Domain   : Computing Theory
% Problem  : T-subst-abs-3 step in progress/preservation proof
% Version  : Especial.
% English  : This problem is a step within the proof of progress and 
%            preservation for the standard type system for the simply-typed 
%            lambda calculus.

% Refs     : [Pie02] Pierce (2002), Programming Languages
%          : [Gre15] Grewe (2015), Email to Geoff Sutcliffe
%          : [GE+15] Grewe et al. (2015), Type Systems for the Masses: Deri
% Source   : [Gre15]
% Names    : SubstLemma-T-subst-abs-3 [Gre15]

% Status   : Theorem
% Rating   : 0.73 v9.0.0, 0.72 v8.2.0, 0.75 v8.1.0, 0.67 v7.5.0, 0.75 v7.4.0, 0.63 v7.3.0, 0.69 v7.1.0, 0.61 v7.0.0, 0.70 v6.4.0
% Syntax   : Number of formulae    :   53 (   6 unt;   0 def)
%            Number of atoms       :  242 ( 171 equ)
%            Maximal formula atoms :   33 (   4 avg)
%            Number of connectives :  221 (  32   ~;  11   |; 100   &)
%                                         (   0 <=>;  78  =>;   0  <=;   0 <~>)
%            Maximal formula depth :   23 (   8 avg)
%            Maximal term depth    :    5 (   1 avg)
%            Number of predicates  :    7 (   5 usr;   1 prp; 0-3 aty)
%            Number of functors    :   13 (  13 usr;   3 con; 0-3 aty)
%            Number of variables   :  275 ( 232   !;  43   ?)
% SPC      : FOF_THM_RFO_SEQ

% Comments : Generated by Veritas: https://github.com/stg-tud/type-pragmatics
%          : This is the original reduced version.
%------------------------------------------------------------------------------
fof('EQ-var',axiom,
    ! [VVar0,VVar1] :
      ( ( vvar(VVar0) = vvar(VVar1)
       => VVar0 = VVar1 )
      & ( VVar0 = VVar1
       => vvar(VVar0) = vvar(VVar1) ) ) ).

fof('EQ-abs',axiom,
    ! [VVar0,VTyp0,VExp0,VVar1,VTyp1,VExp1] :
      ( ( vabs(VVar0,VTyp0,VExp0) = vabs(VVar1,VTyp1,VExp1)
       => ( VVar0 = VVar1
          & VTyp0 = VTyp1
          & VExp0 = VExp1 ) )
      & ( ( VVar0 = VVar1
          & VTyp0 = VTyp1
          & VExp0 = VExp1 )
       => vabs(VVar0,VTyp0,VExp0) = vabs(VVar1,VTyp1,VExp1) ) ) ).

fof('EQ-app',axiom,
    ! [VExp0,VExp1,VExp2,VExp3] :
      ( ( vapp(VExp0,VExp1) = vapp(VExp2,VExp3)
       => ( VExp0 = VExp2
          & VExp1 = VExp3 ) )
      & ( ( VExp0 = VExp2
          & VExp1 = VExp3 )
       => vapp(VExp0,VExp1) = vapp(VExp2,VExp3) ) ) ).

fof('DIFF-var-abs',axiom,
    ! [VVar0,VVar1,VTyp0,VExp0] : vvar(VVar0) != vabs(VVar1,VTyp0,VExp0) ).

fof('DIFF-var-app',axiom,
    ! [VVar0,VExp0,VExp1] : vvar(VVar0) != vapp(VExp0,VExp1) ).

fof('DIFF-abs-app',axiom,
    ! [VVar0,VTyp0,VExp0,VExp1,VExp2] : vabs(VVar0,VTyp0,VExp0) != vapp(VExp1,VExp2) ).

fof(isValue0,axiom,
    ! [Vx,VS,Ve,VExp0] :
      ( VExp0 = vabs(Vx,VS,Ve)
     => visValue(VExp0) ) ).

fof(isValue1,axiom,
    ! [Vx,VExp0] :
      ( VExp0 = vvar(Vx)
     => ~ visValue(VExp0) ) ).

fof(isValue2,axiom,
    ! [Ve1,Ve2,VExp0] :
      ( VExp0 = vapp(Ve1,Ve2)
     => ~ visValue(VExp0) ) ).

fof(isFreeVar0,axiom,
    ! [VVar0,VExp0,Vx,Vv] :
      ( ( VVar0 = Vv
        & VExp0 = vvar(Vx) )
     => ( ( Vx = Vv
         => visFreeVar(VVar0,VExp0) )
        & ( visFreeVar(VVar0,VExp0)
         => Vx = Vv ) ) ) ).

fof(isFreeVar1,axiom,
    ! [VT,VVar0,VExp0,Vx,Vv,Ve] :
      ( ( VVar0 = Vv
        & VExp0 = vabs(Vx,VT,Ve) )
     => ( ( ( Vx != Vv
            & visFreeVar(Vv,Ve) )
         => visFreeVar(VVar0,VExp0) )
        & ( visFreeVar(VVar0,VExp0)
         => ( Vx != Vv
            & visFreeVar(Vv,Ve) ) ) ) ) ).

fof(isFreeVar2,axiom,
    ! [VVar0,VExp0,Ve1,Vv,Ve2] :
      ( ( VVar0 = Vv
        & VExp0 = vapp(Ve1,Ve2) )
     => ( ( ( visFreeVar(Vv,Ve1)
            | visFreeVar(Vv,Ve2) )
         => visFreeVar(VVar0,VExp0) )
        & ( visFreeVar(VVar0,VExp0)
         => ( visFreeVar(Vv,Ve1)
            | visFreeVar(Vv,Ve2) ) ) ) ) ).

fof('EQ-empty',axiom,
    ( ( vempty = vempty
     => $true )
    & ( $true
     => vempty = vempty ) ) ).

fof('EQ-bind',axiom,
    ! [VVar0,VTyp0,VCtx0,VVar1,VTyp1,VCtx1] :
      ( ( vbind(VVar0,VTyp0,VCtx0) = vbind(VVar1,VTyp1,VCtx1)
       => ( VVar0 = VVar1
          & VTyp0 = VTyp1
          & VCtx0 = VCtx1 ) )
      & ( ( VVar0 = VVar1
          & VTyp0 = VTyp1
          & VCtx0 = VCtx1 )
       => vbind(VVar0,VTyp0,VCtx0) = vbind(VVar1,VTyp1,VCtx1) ) ) ).

fof('EQ-noType',axiom,
    ( ( vnoType = vnoType
     => $true )
    & ( $true
     => vnoType = vnoType ) ) ).

fof('EQ-someType',axiom,
    ! [VTyp0,VTyp1] :
      ( ( vsomeType(VTyp0) = vsomeType(VTyp1)
       => VTyp0 = VTyp1 )
      & ( VTyp0 = VTyp1
       => vsomeType(VTyp0) = vsomeType(VTyp1) ) ) ).

fof('DIFF-empty-bind',axiom,
    ! [VVar0,VTyp0,VCtx0] : vempty != vbind(VVar0,VTyp0,VCtx0) ).

fof('DIFF-noType-someType',axiom,
    ! [VTyp0] : vnoType != vsomeType(VTyp0) ).

fof(isSomeType0,axiom,
    ! [VOptTyp0] :
      ( VOptTyp0 = vnoType
     => ~ visSomeType(VOptTyp0) ) ).

fof(isSomeType1,axiom,
    ! [Ve,VOptTyp0] :
      ( VOptTyp0 = vsomeType(Ve)
     => visSomeType(VOptTyp0) ) ).

fof(getSomeType0,axiom,
    ! [VOptTyp0,RESULT,Ve] :
      ( VOptTyp0 = vsomeType(Ve)
     => ( RESULT = vgetSomeType(VOptTyp0)
       => RESULT = Ve ) ) ).

fof(lookup0,axiom,
    ! [Vx,VVar0,VCtx0,RESULT] :
      ( ( VVar0 = Vx
        & VCtx0 = vempty )
     => ( RESULT = vlookup(VVar0,VCtx0)
       => RESULT = vnoType ) ) ).

fof(lookup1,axiom,
    ! [VC,Vx,Vy,VVar0,VCtx0,RESULT,VTy] :
      ( ( VVar0 = Vx
        & VCtx0 = vbind(Vy,VTy,VC) )
     => ( Vx = Vy
       => ( RESULT = vlookup(VVar0,VCtx0)
         => RESULT = vsomeType(VTy) ) ) ) ).

fof(lookup2,axiom,
    ! [VTy,Vy,VVar0,VCtx0,RESULT,Vx,VC] :
      ( ( VVar0 = Vx
        & VCtx0 = vbind(Vy,VTy,VC) )
     => ( Vx != Vy
       => ( RESULT = vlookup(VVar0,VCtx0)
         => RESULT = vlookup(Vx,VC) ) ) ) ).

fof('lookup-INV',axiom,
    ! [VVar0,VCtx0,RESULT] :
      ( vlookup(VVar0,VCtx0) = RESULT
     => ( ? [Vx] :
            ( VVar0 = Vx
            & VCtx0 = vempty
            & RESULT = vnoType )
        | ? [VC,Vx,Vy,VTy] :
            ( VVar0 = Vx
            & VCtx0 = vbind(Vy,VTy,VC)
            & Vx = Vy
            & RESULT = vsomeType(VTy) )
        | ? [VTy,Vy,Vx,VC] :
            ( VVar0 = Vx
            & VCtx0 = vbind(Vy,VTy,VC)
            & Vx != Vy
            & RESULT = vlookup(Vx,VC) ) ) ) ).

fof('T-Context-Duplicate',axiom,
    ! [Vy,VTy,Vx,VTx,VC,Ve,VT] :
      ( ( Vx = Vy
        & vtcheck(vbind(Vx,VTx,vbind(Vy,VTy,VC)),Ve,VT) )
     => vtcheck(vbind(Vx,VTx,VC),Ve,VT) ) ).

fof('T-Context-Swap',axiom,
    ! [Vy,VTy,Vx,VTx,VC,Ve,VT] :
      ( ( Vx != Vy
        & vtcheck(vbind(Vx,VTx,vbind(Vy,VTy,VC)),Ve,VT) )
     => vtcheck(vbind(Vy,VTy,vbind(Vx,VTx,VC)),Ve,VT) ) ).

fof('gensym-is-fresh',axiom,
    ! [Vv,Ve] :
      ( vgensym(Ve) = Vv
     => ~ visFreeVar(Vv,Ve) ) ).

fof(subst0,axiom,
    ! [Vx,Vy,VVar0,VExp0,VExp1,RESULT,Ve] :
      ( ( VVar0 = Vx
        & VExp0 = Ve
        & VExp1 = vvar(Vy) )
     => ( Vx = Vy
       => ( RESULT = vsubst(VVar0,VExp0,VExp1)
         => RESULT = Ve ) ) ) ).

fof(subst1,axiom,
    ! [Ve,Vx,VVar0,VExp0,VExp1,RESULT,Vy] :
      ( ( VVar0 = Vx
        & VExp0 = Ve
        & VExp1 = vvar(Vy) )
     => ( Vx != Vy
       => ( RESULT = vsubst(VVar0,VExp0,VExp1)
         => RESULT = vvar(Vy) ) ) ) ).

fof(subst2,axiom,
    ! [VVar0,VExp0,VExp1,RESULT,Ve1,Vx,Ve,Ve2] :
      ( ( VVar0 = Vx
        & VExp0 = Ve
        & VExp1 = vapp(Ve1,Ve2) )
     => ( RESULT = vsubst(VVar0,VExp0,VExp1)
       => RESULT = vapp(vsubst(Vx,Ve,Ve1),vsubst(Vx,Ve,Ve2)) ) ) ).

fof(subst3,axiom,
    ! [Ve,Vx,VVar0,VExp0,VExp1,RESULT,Vy,VT,Ve1] :
      ( ( VVar0 = Vx
        & VExp0 = Ve
        & VExp1 = vabs(Vy,VT,Ve1) )
     => ( Vx = Vy
       => ( RESULT = vsubst(VVar0,VExp0,VExp1)
         => RESULT = vabs(Vy,VT,Ve1) ) ) ) ).

fof(subst4,axiom,
    ! [VVar0,VExp0,VExp1,RESULT,Vx,Ve,VT,Vy,Vfresh,Ve1] :
      ( ( VVar0 = Vx
        & VExp0 = Ve
        & VExp1 = vabs(Vy,VT,Ve1) )
     => ( ( Vx != Vy
          & visFreeVar(Vy,Ve)
          & Vfresh = vgensym(vapp(vapp(Ve,Ve1),vvar(Vx))) )
       => ( RESULT = vsubst(VVar0,VExp0,VExp1)
         => RESULT = vsubst(Vx,Ve,vabs(Vfresh,VT,vsubst(Vy,vvar(Vfresh),Ve1))) ) ) ) ).

fof(subst5,axiom,
    ! [VVar0,VExp0,VExp1,RESULT,Vy,VT,Vx,Ve,Ve1] :
      ( ( VVar0 = Vx
        & VExp0 = Ve
        & VExp1 = vabs(Vy,VT,Ve1) )
     => ( ( Vx != Vy
          & ~ visFreeVar(Vy,Ve) )
       => ( RESULT = vsubst(VVar0,VExp0,VExp1)
         => RESULT = vabs(Vy,VT,vsubst(Vx,Ve,Ve1)) ) ) ) ).

fof('subst-INV',axiom,
    ! [VVar0,VExp0,VExp1,RESULT] :
      ( vsubst(VVar0,VExp0,VExp1) = RESULT
     => ( ? [Vx,Vy,Ve] :
            ( VVar0 = Vx
            & VExp0 = Ve
            & VExp1 = vvar(Vy)
            & Vx = Vy
            & RESULT = Ve )
        | ? [Ve,Vx,Vy] :
            ( VVar0 = Vx
            & VExp0 = Ve
            & VExp1 = vvar(Vy)
            & Vx != Vy
            & RESULT = vvar(Vy) )
        | ? [Ve1,Vx,Ve,Ve2] :
            ( VVar0 = Vx
            & VExp0 = Ve
            & VExp1 = vapp(Ve1,Ve2)
            & RESULT = vapp(vsubst(Vx,Ve,Ve1),vsubst(Vx,Ve,Ve2)) )
        | ? [Ve,Vx,Vy,VT,Ve1] :
            ( VVar0 = Vx
            & VExp0 = Ve
            & VExp1 = vabs(Vy,VT,Ve1)
            & Vx = Vy
            & RESULT = vabs(Vy,VT,Ve1) )
        | ? [Vx,Ve,VT,Vy,Vfresh,Ve1] :
            ( VVar0 = Vx
            & VExp0 = Ve
            & VExp1 = vabs(Vy,VT,Ve1)
            & Vx != Vy
            & visFreeVar(Vy,Ve)
            & Vfresh = vgensym(vapp(vapp(Ve,Ve1),vvar(Vx)))
            & RESULT = vsubst(Vx,Ve,vabs(Vfresh,VT,vsubst(Vy,vvar(Vfresh),Ve1))) )
        | ? [Vy,VT,Vx,Ve,Ve1] :
            ( VVar0 = Vx
            & VExp0 = Ve
            & VExp1 = vabs(Vy,VT,Ve1)
            & Vx != Vy
            & ~ visFreeVar(Vy,Ve)
            & RESULT = vabs(Vy,VT,vsubst(Vx,Ve,Ve1)) ) ) ) ).

fof('EQ-arrow',axiom,
    ! [VTyp0,VTyp1,VTyp2,VTyp3] :
      ( ( varrow(VTyp0,VTyp1) = varrow(VTyp2,VTyp3)
       => ( VTyp0 = VTyp2
          & VTyp1 = VTyp3 ) )
      & ( ( VTyp0 = VTyp2
          & VTyp1 = VTyp3 )
       => varrow(VTyp0,VTyp1) = varrow(VTyp2,VTyp3) ) ) ).

fof('T-var',axiom,
    ! [VC,Vx,VT] :
      ( vlookup(Vx,VC) = vsomeType(VT)
     => vtcheck(VC,vvar(Vx),VT) ) ).

fof('T-abs',axiom,
    ! [VC,Vx,Ve,VS,VT] :
      ( vtcheck(vbind(Vx,VS,VC),Ve,VT)
     => vtcheck(VC,vabs(Vx,VS,Ve),varrow(VS,VT)) ) ).

fof('T-app',axiom,
    ! [VS,VC,Ve1,Ve2,VT] :
      ( ( vtcheck(VC,Ve1,varrow(VS,VT))
        & vtcheck(VC,Ve2,VS) )
     => vtcheck(VC,vapp(Ve1,Ve2),VT) ) ).

fof('T-inv',axiom,
    ! [Ve,VT,VC] :
      ( vtcheck(VC,Ve,VT)
     => ( ? [Vx] :
            ( Ve = vvar(Vx)
            & vlookup(Vx,VC) = vsomeType(VT) )
        | ? [Vx,Ve2,VT1,VT2] :
            ( Ve = vabs(Vx,VT1,Ve2)
            & VT = varrow(VT1,VT2)
            & vtcheck(vbind(Vx,VT1,VC),Ve2,VT2) )
        | ? [Ve1,Ve2,VS] :
            ( Ve = vapp(Ve1,Ve2)
            & vtcheck(VC,Ve1,varrow(VS,VT))
            & vtcheck(VC,Ve2,VS) ) ) ) ).

fof('T-Weak',axiom,
    ! [Vx,VS,VC,Ve,VT] :
      ( ( vlookup(Vx,VC) = vnoType
        & vtcheck(VC,Ve,VT) )
     => vtcheck(vbind(Vx,VS,VC),Ve,VT) ) ).

fof('T-Strong',axiom,
    ! [Vx,VS,VC,Ve,VT] :
      ( ( ~ visFreeVar(Vx,Ve)
        & vtcheck(vbind(Vx,VS,VC),Ve,VT) )
     => vtcheck(VC,Ve,VT) ) ).

fof('T-Weak-FreeVar',axiom,
    ! [Vx,VS,VC,Ve,VT] :
      ( ( ~ visFreeVar(Vx,Ve)
        & vtcheck(VC,Ve,VT) )
     => vtcheck(vbind(Vx,VS,VC),Ve,VT) ) ).

fof('alpha-equiv-refl',axiom,
    ! [Ve] : valphaEquivalent(Ve,Ve) ).

fof('alpha-equiv-sym',axiom,
    ! [Ve2,Ve1] :
      ( valphaEquivalent(Ve1,Ve2)
     => valphaEquivalent(Ve2,Ve1) ) ).

fof('alpha-equiv-trans',axiom,
    ! [Ve2,Ve1,Ve3] :
      ( ( valphaEquivalent(Ve1,Ve2)
        & valphaEquivalent(Ve2,Ve3) )
     => valphaEquivalent(Ve1,Ve3) ) ).

fof('alpha-equiv-subst-abs',axiom,
    ! [VS,Vx,Vy,Ve] :
      ( ~ visFreeVar(Vy,Ve)
     => valphaEquivalent(vabs(Vx,VS,Ve),vabs(Vy,VS,vsubst(Vx,vvar(Vy),Ve))) ) ).

fof('alpha-equiv-typing',axiom,
    ! [Ve,VC,Ve1,VT] :
      ( ( vtcheck(VC,Ve,VT)
        & valphaEquivalent(Ve,Ve1) )
     => vtcheck(VC,Ve1,VT) ) ).

fof('alpha-equiv-FreeVar',axiom,
    ! [Ve,Vx,Ve1] :
      ( ( ~ visFreeVar(Vx,Ve)
        & valphaEquivalent(Ve,Ve1) )
     => ~ visFreeVar(Vx,Ve1) ) ).

fof('T-subst-abs-2-gen',axiom,
    ! [VT,VC,Vx,Ve,Vy,VS,Ve1,VT2] :
      ( ( Vx != Vy
        & ~ visFreeVar(Vy,Ve)
        & vtcheck(VC,Ve,VT)
        & vtcheck(vbind(Vx,VT,VC),vabs(Vy,VS,Ve1),VT2) )
     => vtcheck(VC,vsubst(Vx,Ve,vabs(Vy,VS,Ve1)),VT2) ) ).

fof('fresh-unequal-var-3',axiom,
    ! [Ve,Ve1,Vx,Vfresh] :
      ( Vfresh = vgensym(vapp(vapp(Ve,Ve1),vvar(Vx)))
     => Vx != Vfresh ) ).

fof('fresh-free-2',axiom,
    ! [Ve,Vx,Vfresh,Ve1] :
      ( Vfresh = vgensym(vapp(vapp(Ve,Ve1),vvar(Vx)))
     => ~ visFreeVar(Vfresh,Ve1) ) ).

fof('T-subst-abs-3',conjecture,
    ! [VT,VC,Vx,Ve,Vy,VS,VT2] :
      ( ( Vx != Vy
        & visFreeVar(Vy,Ve)
        & vtcheck(VC,Ve,VT)
        & vtcheck(vbind(Vx,VT,VC),vabs(Vy,VS,veabs),VT2) )
     => vtcheck(VC,vsubst(Vx,Ve,vabs(Vy,VS,veabs)),VT2) ) ).

%------------------------------------------------------------------------------