Logical Graphs • Discussion 10

Re: Logical Graphs • Formal Development
Re: Laws of FormArmahedi Mahzar

AM:
GSB took J1 : (a(a)) =   as the first algebraic primitive and the second one is transposition so he only need only 2 primitives for the primary algebra.

Reflexion ((a)) = a is proven without using Cancellation (( )) =   .

In fact, he can prove cancellation from C1 reflexion.

Condensation ( )( ) = ( ) can be derived from C4 iteration.

So, his algebra is simpler from your Cactus Calculus.

Dear Arma,

I had a feeling we’ve discussed this before, and probably in a lot more detail than I have time for at the moment, so I hunted up the previous discussion — turns out it was on the old Yahoo Group — there’s a copy of that below for whatever memory‑jogging it may be worth.

To my way of thinking, what you say about reducing the primary arithmetic to the primary algebra shows a lack of appreciation for the fundamental nature of that distinction.  Indeed, the recognition and clarification of that distinction is one of the most important upgrades Spencer Brown added to Peirce’s initial systems of logical graphs.

As far as the other score goes, the advantages of handling label changes and structure changes separately in one’s syntactic operations is just one of those things I learned in the hard knocks way of programming theorem provers for logical graphs, and I all I can do is keep recommending it on that account.

Regards,

Jon

From: Jon Awbrey
To:   Yahoo Laws Of Form
Date: 8/15/2017, 2:10 PM
Re:   Peirce's Law

Arma, All ...

Re: https://intersci.ss.uci.edu/wiki/index.php/Logical_graph#Axioms

Let me try a few ascii graphics to see how this site treats them.

It's clear that the two systems are equivalent, since we have:

 a   a
 o---o
 |
 @
 =======J1′ [delete]
 o---o
 |
 @
 =======I2  [cancel]
 @
 =======QED J1

For my part, I am less concerned with small differences in the lengths
of proofs than I am with other factors.  It's hard for me to remember
all the reasons for decisions I made 40 years ago — as a general rule,
Peirce's way of looking at the relation between mathematics and logic
was and still is very influential and the other main impact came from
the nuts @ and bolts | requirements of computational representation.

But looking at the choice with present eyes, I think I would continue
to prefer the I1, I2, J1′, J2 system over the alternative simply for
the fact that it treats two different types of operation separately,
namely, changes in formal or graphical structure versus changes in
the occurrence or placement of variables.

Regards,

Jon

On 8/14/2017 11:01 PM, armahedi@yahoo.com [lawsofform] wrote:
> Hi Jon
>
> With your answer
>     'Recall that I am using “p(p)=( )” for my J1.
>      I can go back to calling it J1′ if need be.',
> I realize that your axiom system is different from 
> Brownian Primary Algebra.
>
> Here is your axioms
> I1   ()()=()
> I2   (())=
> J1'  (a)a=( )
> J2   ((ab)(ac))=a((b)c)
> and these are Spencer-Brown axioms
> J1   ((a)a)=
> J2   ((ab)(ac))=a((b)(c))
>
> From these axioms you derived three theorems which are 
> identical to the first Spencer-Brown Primary Algebra 
> consequences: Reflection, Generation and Integration.
>
> Here are your proofs in parentheses notation with 
> my critical observations.
>
> You prove Reflection ((a))=a in 8 steps
> ((a))
> =((a))((                 ))           I2
> =((a))((     (a))(     a)))        J1'
> =     ((((a))(a))(((a))a)))      J2
> =     ((        )(((a))a)))         J1'
> =     ((( a ) a )(((a))a)))       J1'
> =    a((( a )   )(((a)) )))        J2
> =    a((                 ))            J1'
> =    a                                  I2
> while in Brownian Primary Algebra the proof is only 6 steps
> because I2+J1'=J1'+I2=J1
>
> You proved Generation (a)b=(ab)b in 5 steps
> (a)b
> =(((a)b))          C1
> =(((a)b))((   ))   I2
> =(((a)b))((b)b)) J1'
> =((a))((b)))b      J2
> =(ab)b               C1
> while in Brownian Primary Algebra the proof is only 4 steps
> because I2+J1'=J1.
>
> You proved Integration a( )=( ) in 2 steps
> a( )
> =a(a)            C2
> =( )               J1'
> While in Brownian Primary Algebra the proof is 3 steps
> because it needs another step C1
> a( )
> =a(a)            C2
> =((a(a)))        C1
> =( )                J1
>
> Comparing the proofs it seems to me that Brownian proof is better 
> because it does not need the arithmetical primitives I1 and I2.
>
> The beauty is that the arithmetical primitives become derived 
> theorems in Brownian Primary Algebra. I2 is J1 with x=   dan 
> I1 is the 4th consequence xx=x with x=( ). So Brownian Primary 
> algebra is more economic than your algebra.
>
> However, it is just my subjective aesthetical preference, your 
> logical superstructure (cactus calculus, differential logic and 
> dynamical logic) is still intact fortunately.
>
> Please correct me if I am wrong.
> Thanks
> Arma

cc: FB | Logical GraphsLaws of FormMathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Amphecks, Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Constraint Satisfaction Problems, Deduction, Diagrammatic Reasoning, Duality, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Minimal Negation Operators, Painted Cacti, Propositional Calculus, Propositional Equation Reasoning Systems, Relation Theory, Semiotics, Sign Relations, Spencer Brown, Topology, Visualization | Tagged , , , , , , , , , , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 8

Exemplary Proofs

Using no more than the axioms and theorems recorded so far, it is possible to prove a multitude of much more complex theorems.  A number of all‑time favorites are linked below.

Resources

cc: FB | Logical Graphs • Laws of Form (1) (2)MathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 7

Frequently Used Theorems (concl.)

C3.  Dominant Form Theorem

The third of the frequently used theorems of service to this survey is one Spencer Brown annotates as Consequence 3 (C3) or Integration.  A better mnemonic might be dominance and recession theorem (DART), but perhaps the brevity of dominant form theorem (DFT) is sufficient reminder of its double‑edged role in proofs.

Dominant Form Theorem

Here is a proof of the Dominant Form Theorem.

Dominant Form Theorem • Proof

Resources

cc: FB | Logical Graphs • Laws of Form (1) (2)MathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 6

Frequently Used Theorems (cont.)

C2.  Generation Theorem

One theorem of frequent use goes under the nickname of the weed and seed theorem (WAST).  The proof is just an exercise in mathematical induction, once a suitable basis is laid down, and it will be left as an exercise for the reader.  What the WAST says is that a label can be freely distributed or freely erased anywhere in a subtree whose root is labeled with that label.

The second in our list of frequently used theorems is in fact the base case of the weed and seed theorem.  In Laws of Form it goes by the names of Consequence 2 (C2) or Generation.

Generation Theorem

Here is a proof of the Generation Theorem.

Generation Theorem • Proof

Resources

cc: FB | Logical Graphs • Laws of Form (1) (2)MathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 5

Frequently Used Theorems

To familiarize ourselves with equational proofs in logical graphs let’s run though the proofs of a few basic theorems in the primary algebra.

C1.  Double Negation Theorem

The first theorem goes under the names of Consequence 1 (C1), the double negation theorem (DNT), or Reflection.

Double Negation Theorem

The proof that follows is adapted from the one George Spencer Brown gave in his book Laws of Form and credited to two of his students, John Dawes and D.A. Utting.

Double Negation Theorem • Proof

Resources

cc: FB | Logical Graphs • Laws of Form (1) (2)MathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 4

Equational Inference

All the initials I_1, I_2, J_1, J_2 have the form of equations.  This means the inference steps they license are reversible.  The proof annotation scheme employed below makes use of double bars =\!=\!=\!=\!=\!= to mark this fact, though it will often be left to the reader to decide which of the two possible directions is the one required for applying the indicated axiom.

The actual business of proof is a far more strategic affair than the routine cranking of inference rules might suggest.  Part of the reason for this lies in the circumstance that the customary types of inference rules combine the moving forward of a state of inquiry with the losing of information along the way that doesn’t appear immediately relevant, at least, not as viewed in the local focus and short run of the proof in question.  Over the long haul, this has the pernicious side‑effect that one is forever strategically required to reconstruct much of the information one had strategically thought to forget at earlier stages of proof, where “before the proof started” can be counted as an earlier stage of the proof in view.

This is just one of the reasons it can be very instructive to study equational inference rules of the sort our axioms have just provided.  Although equational forms of reasoning are paramount in mathematics, they are less familiar to the student of the usual logic textbooks, who may find a few surprises here.

Resources

cc: FB | Logical GraphsLaws of FormMathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 3

Logical Interpretation

One way of assigning logical meaning to the initial equations is known as the entitative interpretation (En).  Under En, the axioms read as follows.

Entitative Interpretation

Another way of assigning logical meaning to the initial equations is known as the existential interpretation (Ex).  Under Ex, the axioms read as follows.

Existential Interpretation

Resources

cc: FB | Logical GraphsLaws of FormMathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 2

Axioms

The formal system of logical graphs is defined by a foursome of formal equations, called initials when regarded purely formally, in abstraction from potential interpretations, and called axioms when interpreted as logical equivalences.  There are two arithmetic initials and two algebraic initials, as shown below.

Arithmetic Initials

Axiom I₁

Axiom I₂

Algebraic Initials

Axiom J₁

Axiom J₂

Resources

cc: FB | Logical GraphsLaws of FormMathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development 1

Logical graphs are next presented as a formal system by going back to the initial elements and developing their consequences in a systematic manner.

Formal Development

Logical Graphs • First Impressions gives an informal introduction to the initial elements of logical graphs and hopefully supplies the reader with an intuitive sense of their motivation and rationale.

The next order of business is to give the precise axioms used to develop the formal system of logical graphs.  The axioms derive from C.S. Peirce’s various systems of graphical syntax via the calculus of indications described in Spencer Brown’s Laws of Form.  The formal proofs to follow will use a variation of Spencer Brown’s annotation scheme to mark each step of the proof according to which axiom is called to license the corresponding step of syntactic transformation, whether it applies to graphs or to strings.

Resources

cc: FB | Logical GraphsLaws of FormMathstodonAcademia.edu
cc: Conceptual GraphsCyberneticsStructural ModelingSystems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 4 Comments

Logical Graphs • Formal Development

Logical graphs are next presented as a formal system by going back to the initial elements and developing their consequences in a systematic manner.

Formal Development

Logical Graphs • First Impressions gives an informal introduction to the initial elements of logical graphs and hopefully supplies the reader with an intuitive sense of their motivation and rationale.

The next order of business is to give the precise axioms used to develop the formal system of logical graphs.  The axioms derive from C.S. Peirce’s various systems of graphical syntax via the calculus of indications described in Spencer Brown’s Laws of Form.  The formal proofs to follow will use a variation of Spencer Brown’s annotation scheme to mark each step of the proof according to which axiom is called to license the corresponding step of syntactic transformation, whether it applies to graphs or to strings.

Axioms

The formal system of logical graphs is defined by a foursome of formal equations, called initials when regarded purely formally, in abstraction from potential interpretations, and called axioms when interpreted as logical equivalences.  There are two arithmetic initials and two algebraic initials, as shown below.

Arithmetic Initials

Axiom I₁

Axiom I₂

Algebraic Initials

Axiom J₁

Axiom J₂

Logical Interpretation

One way of assigning logical meaning to the initial equations is known as the entitative interpretation (En).  Under En, the axioms read as follows.

\begin{array}{ccccc}  \mathrm{I_1}  & : & \text{true} ~ \text{or} ~ \text{true}  & = & \text{true}  \\[4pt]  \mathrm{I_2}  & : & \text{not} ~ \text{true}  & = & \text{false}  \\[4pt]  \mathrm{J_1}  & : & a ~ \text{or} ~ \text{not} ~ a  & = & \text{true}  \\[4pt]  \mathrm{J_2}  & : & (a ~ \text{or} ~ b) ~ \text{and} ~ (a ~ \text{or} ~ c)  & = & a ~ \text{or} ~ (b ~ \text{and} ~ c)  \end{array}

Another way of assigning logical meaning to the initial equations is known as the existential interpretation (Ex).  Under Ex, the axioms read as follows.

\begin{array}{ccccc}  \mathrm{I_1}  & : & \text{false} ~ \text{and} ~ \text{false}  & = & \text{false}  \\[4pt]  \mathrm{I_2}  & : & \text{not} ~ \text{false}  & = & \text{true}  \\[4pt]  \mathrm{J_1}  & : & a ~ \text{and} ~ \text{not} ~ a   & = & \text{false}  \\[4pt]  \mathrm{J_2}  & : & (a ~ \text{and} ~ b) ~ \text{or} ~ (a\ \text{and}\ c)  & = & a ~ \text{and} ~ (b ~ \text{or} ~ c)  \end{array}

Equational Inference

All the initials I_1, I_2, J_1, J_2 have the form of equations.  This means the inference steps they license are reversible.  The proof annotation scheme employed below makes use of double bars =\!=\!=\!=\!=\!= to mark this fact, though it will often be left to the reader to decide which of the two possible directions is the one required for applying the indicated axiom.

The actual business of proof is a far more strategic affair than the routine cranking of inference rules might suggest.  Part of the reason for this lies in the circumstance that the customary types of inference rules combine the moving forward of a state of inquiry with the losing of information along the way that doesn’t appear immediately relevant, at least, not as viewed in the local focus and short run of the proof in question.  Over the long haul, this has the pernicious side‑effect that one is forever strategically required to reconstruct much of the information one had strategically thought to forget at earlier stages of proof, where “before the proof started” can be counted as an earlier stage of the proof in view.

This is just one of the reasons it can be very instructive to study equational inference rules of the sort our axioms have just provided.  Although equational forms of reasoning are paramount in mathematics, they are less familiar to the student of the usual logic textbooks, who may find a few surprises here.

Frequently Used Theorems

To familiarize ourselves with equational proofs in logical graphs let’s run though the proofs of a few basic theorems in the primary algebra.

C1.  Double Negation Theorem

The first theorem goes under the names of Consequence 1 (C1), the double negation theorem (DNT), or Reflection.

Double Negation Theorem

The proof that follows is adapted from the one George Spencer Brown gave in his book Laws of Form and credited to two of his students, John Dawes and D.A. Utting.

Double Negation Theorem • Proof

C2.  Generation Theorem

One theorem of frequent use goes under the nickname of the weed and seed theorem (WAST).  The proof is just an exercise in mathematical induction, once a suitable basis is laid down, and it will be left as an exercise for the reader.  What the WAST says is that a label can be freely distributed or freely erased anywhere in a subtree whose root is labeled with that label.  The second in our list of frequently used theorems is in fact the base case of the weed and seed theorem.  In Laws of Form it goes by the names of Consequence 2 (C2) or Generation.

Generation Theorem

Here is a proof of the Generation Theorem.

Generation Theorem • Proof

C3.  Dominant Form Theorem

The third of the frequently used theorems of service to this survey is one Spencer Brown annotates as Consequence 3 (C3) or Integration.  A better mnemonic might be dominance and recession theorem (DART), but perhaps the brevity of dominant form theorem (DFT) is sufficient reminder of its double‑edged role in proofs.

Dominant Form Theorem

Here is a proof of the Dominant Form Theorem.

Dominant Form Theorem • Proof

Exemplary Proofs

Using no more than the axioms and theorems recorded so far, it is possible to prove a multitude of much more complex theorems.  A couple of all‑time favorites are listed below.

Resources

cc: FB | Logical Graphs • Laws of Form • Mathstodon • Academia.edu
cc: Conceptual Graphs • Cybernetics • Structural Modeling • Systems Science

Posted in Animata, Boolean Algebra, Boolean Functions, C.S. Peirce, Cactus Graphs, Deduction, Equational Inference, Graph Theory, Laws of Form, Logic, Logical Graphs, Mathematics, Propositional Calculus, Propositional Equation Reasoning Systems, Semiotics, Spencer Brown, Visualization | Tagged , , , , , , , , , , , , , , , , | 8 Comments