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| Table 1 collects a sample of basic propositional forms as expressed in terms of cactus language connectives. | | Table 1 collects a sample of basic propositional forms as expressed in terms of cactus language connectives. |
| | | |
− | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:90%" | + | <br> |
− | |+ <math>\text{Table 1.}~~\text{Syntax and Semantics of a Calculus for Propositional Logic}\!</math> | + | |
− | |- style="background:#f0f0ff" | + | {| align="center" border="1" cellpadding="8" cellspacing="0" style="text-align:center; width:75%" |
− | | <math>\text{Graph}\!</math>
| + | |+ style="height:30px" | <math>\text{Table 1.} ~~ \text{Syntax and Semantics of a Calculus for Propositional Logic}\!</math> |
| + | |- style="height:40px; background:ghostwhite" |
| | <math>\text{Expression}~\!</math> | | | <math>\text{Expression}~\!</math> |
| | <math>\text{Interpretation}\!</math> | | | <math>\text{Interpretation}\!</math> |
| | <math>\text{Other Notations}\!</math> | | | <math>\text{Other Notations}\!</math> |
| |- | | |- |
− | | height="100px" | [[Image:Rooted Node.jpg|20px]] | + | | |
− | | <math>~\!</math>
| + | | <math>\text{True}\!</math> |
− | | <math>\mathrm{true}\!</math> | |
| | <math>1\!</math> | | | <math>1\!</math> |
| |- | | |- |
− | | height="100px" | [[Image:Rooted Edge.jpg|20px]]
| |
| | <math>\texttt{(~)}\!</math> | | | <math>\texttt{(~)}\!</math> |
− | | <math>\mathrm{false}\!</math> | + | | <math>\text{False}\!</math> |
| | <math>0\!</math> | | | <math>0\!</math> |
| |- | | |- |
− | | height="100px" | [[Image:Cactus A Big.jpg|20px]]
| + | | <math>x\!</math> |
− | | <math>a\!</math> | + | | <math>x\!</math> |
− | | <math>a\!</math> | + | | <math>x\!</math> |
− | | <math>a\!</math> | |
| |- | | |- |
− | | height="120px" | [[Image:Cactus (A) Big.jpg|20px]]
| + | | <math>\texttt{(} x \texttt{)}\!</math> |
− | | <math>\texttt{(} a \texttt{)}\!</math> | + | | <math>\text{Not}~ x\!</math> |
− | | <math>\mathrm{not}~ a\!</math> | + | | |
− | | <math>\lnot a \quad \bar{a} \quad \tilde{a} \quad a^\prime~\!</math> | + | <math>\begin{matrix} |
| + | x' |
| + | \\ |
| + | \tilde{x} |
| + | \\ |
| + | \lnot x |
| + | \end{matrix}\!</math> |
| |- | | |- |
− | | height="100px" | [[Image:Cactus ABC Big.jpg|50px]]
| + | | <math>x~y~z\!</math> |
− | | <math>a ~ b ~ c\!</math> | + | | <math>x ~\text{and}~ y ~\text{and}~ z\!</math> |
− | | <math>a ~\mathrm{and}~ b ~\mathrm{and}~ c\!</math> | + | | <math>x \land y \land z\!</math> |
− | | <math>a \land b \land c\!</math> | |
| |- | | |- |
− | | height="160px" | [[Image:Cactus ((A)(B)(C)) Big.jpg|65px]]
| + | | <math>\texttt{((} x \texttt{)(} y \texttt{)(} z \texttt{))}\!</math> |
− | | <math>\texttt{((} a \texttt{)(} b \texttt{)(} c \texttt{))}\!</math> | + | | <math>x ~\text{or}~ y ~\text{or}~ z\!</math> |
− | | <math>a ~\mathrm{or}~ b ~\mathrm{or}~ c\!</math> | + | | <math>x \lor y \lor z\!</math> |
− | | <math>a \lor b \lor c\!</math> | |
| |- | | |- |
− | | height="120px" | [[Image:Cactus (A(B)) Big.jpg|60px]]
| + | | <math>\texttt{(} x ~ \texttt{(} y \texttt{))}\!</math> |
− | | <math>\texttt{(} a \texttt{(} b \texttt{))}\!</math> | |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | a ~\text{implies}~ b
| + | x ~\text{implies}~ y |
− | \\[6pt] | + | \\ |
− | \mathrm{if}~ a ~\mathrm{then}~ b | + | \mathrm{If}~ x ~\text{then}~ y |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
− | | <math>a \Rightarrow b\!</math> | + | | <math>x \Rightarrow y\!</math> |
| |- | | |- |
− | | height="120px" | [[Image:Cactus (A,B) Big ISW.jpg|65px]]
| + | | <math>\texttt{(} x \texttt{,} y \texttt{)}\!</math> |
− | | <math>\texttt{(} a \texttt{,} b \texttt{)}\!</math> | |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | a ~\mathrm{not~equal~to}~ b
| + | x ~\text{not equal to}~ y |
− | \\[6pt] | + | \\ |
− | a ~\mathrm{exclusive~or}~ b
| + | x ~\text{exclusive or}~ y |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | a \neq b
| + | x \ne y |
− | \\[6pt] | + | \\ |
− | a + b
| + | x + y |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| |- | | |- |
− | | height="160px" | [[Image:Cactus ((A,B)) Big.jpg|65px]]
| + | | <math>\texttt{((} x \texttt{,} y \texttt{))}\!</math> |
− | | <math>\texttt{((} a \texttt{,} b \texttt{))}\!</math> | |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | a ~\mathrm{is~equal~to}~ b
| + | x ~\text{is equal to}~ y |
− | \\[6pt] | + | \\ |
− | a ~\mathrm{if~and~only~if}~ b
| + | x ~\text{if and only if}~ y |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | a = b
| + | x = y |
− | \\[6pt] | + | \\ |
− | a \Leftrightarrow b
| + | x \Leftrightarrow y |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| |- | | |- |
− | | height="120px" | [[Image:Cactus (A,B,C) Big.jpg|65px]]
| + | | <math>\texttt{(} x \texttt{,} y \texttt{,} z \texttt{)}\!</math> |
− | | <math>\texttt{(} a \texttt{,} b \texttt{,} c \texttt{)}\!</math> | |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | \mathrm{just~one~of} | + | \text{Just one of} |
| \\ | | \\ |
− | a, b, c
| + | x, y, z |
| \\ | | \\ |
− | \mathrm{is~false}. | + | \text{is false}. |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | & \bar{a} ~ b ~ c | + | x'y~z~ & \lor |
| \\ | | \\ |
− | \lor & a ~ \bar{b} ~ c | + | x~y'z~ & \lor |
| \\ | | \\ |
− | \lor & a ~ b ~ \bar{c}
| + | x~y~z' & |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| |- | | |- |
− | | height="160px" | [[Image:Cactus ((A),(B),(C)) Big.jpg|65px]]
| + | | <math>\texttt{((} x \texttt{),(} y \texttt{),(} z \texttt{))}\!</math> |
− | | <math>\texttt{((} a \texttt{),(} b \texttt{),(} c \texttt{))}\!</math> | |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | \mathrm{just~one~of} | + | \text{Just one of} |
| + | \\ |
| + | x, y, z |
| + | \\ |
| + | \text{is true}. |
| + | \\ |
| + | & |
| + | \\ |
| + | \text{Partition all} |
| \\ | | \\ |
− | a, b, c
| + | \text{into}~ x, y, z. |
| + | \end{matrix}</math> |
| + | | |
| + | <math>\begin{matrix} |
| + | x~y'z' & \lor |
| \\ | | \\ |
− | \mathrm{is~true}.
| + | x'y~z' & \lor |
− | \\[6pt]
| |
− | \mathrm{partition~all} | |
| \\ | | \\ |
− | \mathrm{into}~ a, b, c.
| + | x'y'z~ & |
− | \end{matrix}\!</math> | + | \end{matrix}</math> |
| + | |- |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | & a ~ \bar{b} ~ \bar{c}
| + | \texttt{((} x \texttt{,} y \texttt{),} z \texttt{)} |
| \\ | | \\ |
− | \lor & \bar{a} ~ b ~ \bar{c}
| + | & |
| \\ | | \\ |
− | \lor & \bar{a} ~ \bar{b} ~ c | + | \texttt{(} x \texttt{,(} y \texttt{,} z \texttt{))} |
| \end{matrix}\!</math> | | \end{matrix}\!</math> |
− | |-
| |
− | | height="160px" | [[Image:Cactus (A,(B,C)) Big.jpg|90px]]
| |
− | | <math>\texttt{(} a \texttt{,(} b \texttt{,} c \texttt{))}\!</math>
| |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | \mathrm{oddly~many~of} | + | \text{Oddly many of} |
| \\ | | \\ |
− | a, b, c
| + | x, y, z |
| \\ | | \\ |
− | \mathrm{are~true}. | + | \text{are true}. |
| \end{matrix}\!</math> | | \end{matrix}\!</math> |
| | | | | |
− | <p><math>a + b + c\!</math></p> | + | <p><math>x + y + z\!</math></p> |
| <br> | | <br> |
| <p><math>\begin{matrix} | | <p><math>\begin{matrix} |
− | & a ~ b ~ c
| + | x~y~z~ & \lor |
| \\ | | \\ |
− | \lor & a ~ \bar{b} ~ \bar{c} | + | x~y'z' & \lor |
| \\ | | \\ |
− | \lor & \bar{a} ~ b ~ \bar{c} | + | x'y~z' & \lor |
| \\ | | \\ |
− | \lor & \bar{a} ~ \bar{b} ~ c
| + | x'y'z~ & |
| \end{matrix}\!</math></p> | | \end{matrix}\!</math></p> |
| |- | | |- |
− | | height="160px" | [[Image:Cactus (X,(A),(B),(C)) Big.jpg|90px]]
| + | | <math>\texttt{(} w \texttt{,(} x \texttt{),(} y \texttt{),(} z \texttt{))}\!</math> |
− | | <math>\texttt{(} x \texttt{,(} a \texttt{),(} b \texttt{),(} c \texttt{))}\!</math> | |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | \mathrm{partition}~ x | + | \text{Partition}~ w |
| \\ | | \\ |
− | \mathrm{into}~ a, b, c. | + | \text{into}~ x, y, z. |
− | \\[6pt]
| |
− | \mathrm{genus}~ x ~\mathrm{comprises}
| |
| \\ | | \\ |
− | \mathrm{species}~ a, b, c. | + | & |
− | \end{matrix}\!</math> | + | \\ |
| + | \text{Genus}~ w ~\text{comprises} |
| + | \\ |
| + | \text{species}~ x, y, z. |
| + | \end{matrix}</math> |
| | | | | |
| <math>\begin{matrix} | | <math>\begin{matrix} |
− | & \bar{x} ~ \bar{a} ~ \bar{b} ~ \bar{c} | + | w'x'y'z' & \lor |
| \\ | | \\ |
− | \lor & x ~ a ~ \bar{b} ~ \bar{c}
| + | w~x~y'z' & \lor |
| \\ | | \\ |
− | \lor & x ~ \bar{a} ~ b ~ \bar{c}
| + | w~x'y~z' & \lor |
| \\ | | \\ |
− | \lor & x ~ \bar{a} ~ \bar{b} ~ c
| + | w~x'y'z~ & |
− | \end{matrix}~\!</math> | + | \end{matrix}</math> |
| |} | | |} |
| + | |
| + | <br> |
| | | |
| The simplest expression for logical truth is the empty word, usually denoted by <math>\boldsymbol\varepsilon\!</math> or <math>\lambda\!</math> in formal languages, where it forms the identity element for concatenation. To make it visible in context, it may be denoted by the equivalent expression <math>{}^{\backprime\backprime} \texttt{((~))} {}^{\prime\prime},\!</math> or, especially if operating in an algebraic context, by a simple <math>{}^{\backprime\backprime} 1 {}^{\prime\prime}.\!</math> Also when working in an algebraic mode, the plus sign <math>{}^{\backprime\backprime} + {}^{\prime\prime}\!</math> may be used for [[exclusive disjunction]]. For example, we have the following paraphrases of algebraic expressions by means of parenthesized expressions: | | The simplest expression for logical truth is the empty word, usually denoted by <math>\boldsymbol\varepsilon\!</math> or <math>\lambda\!</math> in formal languages, where it forms the identity element for concatenation. To make it visible in context, it may be denoted by the equivalent expression <math>{}^{\backprime\backprime} \texttt{((~))} {}^{\prime\prime},\!</math> or, especially if operating in an algebraic context, by a simple <math>{}^{\backprime\backprime} 1 {}^{\prime\prime}.\!</math> Also when working in an algebraic mode, the plus sign <math>{}^{\backprime\backprime} + {}^{\prime\prime}\!</math> may be used for [[exclusive disjunction]]. For example, we have the following paraphrases of algebraic expressions by means of parenthesized expressions: |