12,080
edits
Changes
Directory:Jon Awbrey/Papers/Propositional Equation Reasoning Systems (view source)
Revision as of 16:21, 18 August 2009
, 16:21, 18 August 2009del redun & renum figs
|}
|}
It remains to show that the right hand side of the equation <math>\texttt{(} p \texttt{(} q \texttt{))(} p \texttt{(} r \texttt{))} = \texttt{(} p \texttt{(} q r \texttt{))}</math> is logically equivalent to the DNF just obtained. The remainder of the needed chain of equations is as follows:
{| align="center" cellpadding="8" style="text-align:center; width:90%"
{| align="center" cellpadding="8" style="text-align:center; width:90%"
o=============================< DNF >=======================o
o=============================< DNF >=======================o
</pre>
</pre>
| (34)
| (33)
|}
|}
o-----------------------------------------------------------o
o-----------------------------------------------------------o
</pre>
</pre>
| (35)
| (34)
|}
|}
o-----------------------------------------------------------o
o-----------------------------------------------------------o
</pre>
</pre>
| (36)
| (35)
|}
|}
o-----------------------------------------------------------o
o-----------------------------------------------------------o
</pre>
</pre>
| (37)
| (36)
|}
|}
o-----------------------------------------------------------o
o-----------------------------------------------------------o
</pre>
</pre>
| (38)
| (37)
|}
|}
o-----------------------------------------------------------o
o-----------------------------------------------------------o
</pre>
</pre>
| (39)
| (38)
|}
|}
o-----------------------------------------------------------o
o-----------------------------------------------------------o
</pre>
</pre>
| (40)
| (39)
|}
|}
o==================================< QED >==================o
o==================================< QED >==================o
</pre>
</pre>
| (41)
| (40)
|}
|}
{| align="center" cellpadding="6" style="text-align:center"
{| align="center" cellpadding="6" style="text-align:center"
| [[Image:Venn Diagram (P (Q)).jpg|500px]] || (43)
| [[Image:Venn Diagram (P (Q)).jpg|500px]] || (42)
|-
|-
| <math>f_{207}(p, q, r) ~=~ \texttt{(} p \texttt{~(} q \texttt{))}</math>
| <math>f_{207}(p, q, r) ~=~ \texttt{(} p \texttt{~(} q \texttt{))}</math>
|
|
|-
|-
| [[Image:Venn Diagram (Q (R)).jpg|500px]] || (44)
| [[Image:Venn Diagram (Q (R)).jpg|500px]] || (43)
|-
|-
| <math>f_{187}(p, q, r) ~=~ \texttt{(} q \texttt{~(} r \texttt{))}</math>
| <math>f_{187}(p, q, r) ~=~ \texttt{(} q \texttt{~(} r \texttt{))}</math>
|
|
|-
|-
| [[Image:Venn Diagram (P (R)).jpg|500px]] || (45)
| [[Image:Venn Diagram (P (R)).jpg|500px]] || (44)
|-
|-
| <math>f_{175}(p, q, r) ~=~ \texttt{(} p \texttt{~(} r \texttt{))}</math>
| <math>f_{175}(p, q, r) ~=~ \texttt{(} p \texttt{~(} r \texttt{))}</math>
|
|
|-
|-
| [[Image:Venn Diagram (P (Q)) (Q (R)).jpg|500px]] || (46)
| [[Image:Venn Diagram (P (Q)) (Q (R)).jpg|500px]] || (45)
|-
|-
| <math>f_{139}(p, q, r) ~=~ \texttt{(} p \texttt{~(} q \texttt{))~(} q \texttt{~(} r \texttt{))}</math>
| <math>f_{139}(p, q, r) ~=~ \texttt{(} p \texttt{~(} q \texttt{))~(} q \texttt{~(} r \texttt{))}</math>
But the more I survey the problem setting the more it looks like we need better ways to bring our visual intuitions to play on the scene, and so let us next lay out some visual schemata that are designed to facilitate that.
But the more I survey the problem setting the more it looks like we need better ways to bring our visual intuitions to play on the scene, and so let us next lay out some visual schemata that are designed to facilitate that.
Figure 28-a shows the familiar picture of a boolean 3-cube, where the points of <math>\mathbb{B}^3</math> are coordinated as bit strings of length three. Looking at the functions <math>f : \mathbb{B}^3 \to \mathbb{B}</math> and the relations <math>L \subseteq \mathbb{B}^3</math> on this pattern, one views the construction of either type of object as a matter of coloring the nodes of the 3-cube with choices from a pair of colors that stipulate which points are in the relation <math>L = [| f |]\!</math> and which points are out of it. Bowing to common convention, we may use the color <math>1\!</math> for points that are ''in'' a given relation and the color <math>0\!</math> for points that are ''out'' of the same relation. However, it will be more convenient here to indicate the former case by writing the coordinates in the place of the node and to indicate the latter case by plotting the point as an unlabeled node "o".
Figure 52 shows the familiar picture of a boolean 3-cube, where the points of <math>\mathbb{B}^3</math> are coordinated as bit strings of length three. Looking at the functions <math>f : \mathbb{B}^3 \to \mathbb{B}</math> and the relations <math>L \subseteq \mathbb{B}^3</math> on this pattern, one views the construction of either type of object as a matter of coloring the nodes of the 3-cube with choices from a pair of colors that stipulate which points are in the relation <math>L = [| f |]\!</math> and which points are out of it. Bowing to common convention, we may use the color <math>1\!</math> for points that are ''in'' a given relation and the color <math>0\!</math> for points that are ''out'' of the same relation. However, it will be more convenient here to indicate the former case by writing the coordinates in the place of the node and to indicate the latter case by plotting the point as an unlabeled node "o".
{| align="center" cellpadding="10" style="text-align:center; width:90%"
{| align="center" cellpadding="10" style="text-align:center; width:90%"
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 28-a. Boolean 3-Cube B^3
Figure 52. Boolean 3-Cube B^3
</pre>
</pre>
| (53)
| (52)
|}
|}
Table 54 shows the 3-adic relation <math>\operatorname{Syll} \subseteq \mathbb{B}^3</math> again, and Figure 55 shows it plotted on a 3-cube template.
Table 53 shows the 3-adic relation <math>\operatorname{Syll} \subseteq \mathbb{B}^3</math> again, and Figure 54 shows it plotted on a 3-cube template.
{| align="center" cellpadding="10" style="text-align:center; width:90%"
{| align="center" cellpadding="10" style="text-align:center; width:90%"
|
|
<pre>
<pre>
Table 54. Syll c B^3
Table 53. Syll c B^3
o-----------------------o
o-----------------------o
| p q r |
| p q r |
o-----------------------o
o-----------------------o
</pre>
</pre>
| (54)
| (53)
|-
|-
|
|
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 55. Triadic Relation Syll c B^3
Figure 54. Triadic Relation Syll c B^3
</pre>
</pre>
| (55)
| (54)
|}
|}
|
|
<pre>
<pre>
Table 56. Syll c B^3
Table 55. Syll c B^3
o-----------------------o
o-----------------------o
| p q r |
| p q r |
o-----------------------o
o-----------------------o
</pre>
</pre>
| (56)
| (55)
|-
|-
|
|
<pre>
<pre>
Table 57. Dyadic Projections of Syll
Table 56. Dyadic Projections of Syll
o-----------o o-----------o o-----------o
o-----------o o-----------o o-----------o
| Syll_12 | | Syll_13 | | Syll_23 |
| Syll_12 | | Syll_13 | | Syll_23 |
o-----------o o-----------o o-----------o
o-----------o o-----------o o-----------o
</pre>
</pre>
| (57)
| (56)
|}
|}
In showing the 2-adic projections of a 3-adic relation <math>L \subseteq \mathbb{B}^3,</math> I will translate the coordinates of the points in each relation to the plane of the projection, there dotting out with a dot "." the bit of the bit string that is out of place on that plane.
In showing the 2-adic projections of a 3-adic relation <math>L \subseteq \mathbb{B}^3,</math> I will translate the coordinates of the points in each relation to the plane of the projection, there dotting out with a dot "." the bit of the bit string that is out of place on that plane.
Figure 58 shows <math>\operatorname{Syll}</math> and its three 2-adic projections:
Figure 57 shows <math>\operatorname{Syll}</math> and its three 2-adic projections:
{| align="center" cellpadding="10" style="text-align:center; width:90%"
{| align="center" cellpadding="10" style="text-align:center; width:90%"
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 58. Syll c B^3 and its Dyadic Projections
Figure 57. Syll c B^3 and its Dyadic Projections
</pre>
</pre>
| (58)
| (57)
|}
|}
|
|
<pre>
<pre>
Table 59. Syll c B^3
Table 58. Syll c B^3
o-----------------------o
o-----------------------o
| p q r |
| p q r |
o-----------------------o
o-----------------------o
</pre>
</pre>
| (59)
| (58)
|-
|-
|
|
<pre>
<pre>
Table 60. Dyadic Projections of Syll
Table 59. Dyadic Projections of Syll
o-----------o o-----------o o-----------o
o-----------o o-----------o o-----------o
| Syll_12 | | Syll_13 | | Syll_23 |
| Syll_12 | | Syll_13 | | Syll_23 |
o-----------o o-----------o o-----------o
o-----------o o-----------o o-----------o
</pre>
</pre>
| (60)
| (59)
|-
|-
|
|
<pre>
<pre>
Table 61. Tacit Extensions of Projections of Syll
Table 60. Tacit Extensions of Projections of Syll
o---------------o o---------------o o---------------o
o---------------o o---------------o o---------------o
| te(Syll_12) | | te(Syll_13) | | te(Syll_23) |
| te(Syll_12) | | te(Syll_13) | | te(Syll_23) |
o---------------o o---------------o o---------------o
o---------------o o---------------o o---------------o
</pre>
</pre>
| (61)
| (60)
|-
|-
|
|
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 62. Tacit Extension te_12_3 (Syll_12)
Figure 61. Tacit Extension te_12_3 (Syll_12)
</pre>
</pre>
| (62)
| (61)
|-
|-
|
|
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 63. Tacit Extension te_13_2 (Syll_13)
Figure 62. Tacit Extension te_13_2 (Syll_13)
</pre>
</pre>
| (63)
| (62)
|-
|-
|
|
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 64. Tacit Extension te_23_1 (Syll_23)
Figure 63. Tacit Extension te_23_1 (Syll_23)
</pre>
</pre>
| (64)
| (63)
|}
|}
The reader may wish to contemplate Figure 31 and use it to verify the following two facts:
The reader may wish to contemplate Figure 64 and use it to verify the following two facts:
{| align="center" cellpadding="8" width="90%"
{| align="center" cellpadding="8" width="90%"
| |
| |
o-------------------------------------------------o
o-------------------------------------------------o
Figure 65. Syll = te(Syll_12) |^| te(Syll_23)
Figure 64. Syll = te(Syll_12) |^| te(Syll_23)
</pre>
</pre>
| (65)
| (64)
|}
|}
In accord with my experimental way, I will stick with the case of transitive inference until I have pinned it down thoroughly, but of course the real interest is much more general than that.
In accord with my experimental way, I will stick with the case of transitive inference until I have pinned it down thoroughly, but of course the real interest is much more general than that.
At first or maybe second sight, the relationships seem easy enough to write out. Figure 66 shows how the various logical expressions are related to each other: The expressions "(p (q))" and "(q (r))" are conjoined in a purely syntactic fashion — much in the way that one might compile a theory from axioms without knowing what either the theory or the axioms were about — and the best way to sum up the state of information implicit in taking them together is just the expression "(p (q)) (q (r))" that would the canonical result of an equational or reversible rule of inference. From that equational inference, one might arrive at the implicational inference "(p (r))" by the most conventional implication.
At first or maybe second sight, the relationships seem easy enough to write out. Figure 65 shows how the various logical expressions are related to each other: The expressions "(p (q))" and "(q (r))" are conjoined in a purely syntactic fashion — much in the way that one might compile a theory from axioms without knowing what either the theory or the axioms were about — and the best way to sum up the state of information implicit in taking them together is just the expression "(p (q)) (q (r))" that would the canonical result of an equational or reversible rule of inference. From that equational inference, one might arrive at the implicational inference "(p (r))" by the most conventional implication.
<pre>
<pre>
o-------------------o
o-------------------o
Figure 66. Expressive Aspects of Transitive Inference
Figure 65. Expressive Aspects of Transitive Inference
</pre>
</pre>
Despite how simple the formulaic aspects of transitive inference might appear on the surface, there are problems that wait for us just beneath the syntactic surface, as we quickly discover if we turn to considering the kinds of objects, abstract and concrete, that these formulas are meant to denote, and all the more so if we try to do this in a context of computational implementations, where the "interpreters" to be addressed take nothing on faith. Thus we engage the ''denotative semantics'' or the ''model theory'' of these extremely simple programs that we call ''propositions''.
Despite how simple the formulaic aspects of transitive inference might appear on the surface, there are problems that wait for us just beneath the syntactic surface, as we quickly discover if we turn to considering the kinds of objects, abstract and concrete, that these formulas are meant to denote, and all the more so if we try to do this in a context of computational implementations, where the "interpreters" to be addressed take nothing on faith. Thus we engage the ''denotative semantics'' or the ''model theory'' of these extremely simple programs that we call ''propositions''.
Figure 66 is an attempt to outline the model-theoretic relationships that are involved in our study of transitive inference. A couple of alternative notations are introduced in this Table:
{| align="center" cellpadding="8" width="90%"
{| align="center" cellpadding="8" width="90%"
o---------o---------o o---------o---------o
o---------o---------o o---------o---------o
Figure 67. Denotative Aspects of Transitive Inference
Figure 66. Denotative Aspects of Transitive Inference
</pre>
</pre>
An abstract reference to a point of <math>X\!</math> is a triple in <math>\mathbb{B}^3.</math> A concrete reference to a point of <math>X\!</math> is a conjunction of signs from the dimensions <math>P^\ddagger, Q^\ddagger, R^\ddagger,</math> picking exactly one sign from each dimension.
An abstract reference to a point of <math>X\!</math> is a triple in <math>\mathbb{B}^3.</math> A concrete reference to a point of <math>X\!</math> is a conjunction of signs from the dimensions <math>P^\ddagger, Q^\ddagger, R^\ddagger,</math> picking exactly one sign from each dimension.
To illustrate the use of concrete coordinates for points and concrete types for spaces and propositions, Figure 68 translates the contents of Figure 33 into the new language.
To illustrate the use of concrete coordinates for points and concrete types for spaces and propositions, Figure 67 translates the contents of Figure 66 into the new language.
<pre>
<pre>
o---------o---------o o---------o---------o
o---------o---------o o---------o---------o
Figure 68. Denotative Aspects of Transitive Inference
Figure 67. Denotative Aspects of Transitive Inference
</pre>
</pre>