This site is supported by donations to The OEIS Foundation.
Table 1 shows the cactus graphs, the corresponding cactus expressions, their logical meanings under the so-called existential interpretation, and their translations into conventional notations for a sample of basic propositional forms.
a i m p l i e s b i f a t h e n b {\displaystyle {\begin{matrix}a~\mathrm {implies} ~b\\[6pt]\mathrm {if} ~a~\mathrm {then} ~b\end{matrix}}}
a n o t e q u a l t o b a e x c l u s i v e o r b {\displaystyle {\begin{matrix}a~\mathrm {not~equal~to} ~b\\[6pt]a~\mathrm {exclusive~or} ~b\end{matrix}}}
a ≠ b a + b {\displaystyle {\begin{matrix}a\neq b\\[6pt]a+b\end{matrix}}}
a i s e q u a l t o b a i f a n d o n l y i f b {\displaystyle {\begin{matrix}a~\mathrm {is~equal~to} ~b\\[6pt]a~\mathrm {if~and~only~if} ~b\end{matrix}}}
a = b a ⇔ b {\displaystyle {\begin{matrix}a=b\\[6pt]a\Leftrightarrow b\end{matrix}}}
j u s t o n e o f a , b , c i s f a l s e . {\displaystyle {\begin{matrix}\mathrm {just~one~of} \\a,b,c\\\mathrm {is~false} .\end{matrix}}}
a ¯ b c ∨ a b ¯ c ∨ a b c ¯ {\displaystyle {\begin{matrix}&{\bar {a}}~b~c\\\lor &a~{\bar {b}}~c\\\lor &a~b~{\bar {c}}\end{matrix}}}
j u s t o n e o f a , b , c i s t r u e . p a r t i t i o n a l l i n t o a , b , c . {\displaystyle {\begin{matrix}\mathrm {just~one~of} \\a,b,c\\\mathrm {is~true} .\\[6pt]\mathrm {partition~all} \\\mathrm {into} ~a,b,c.\end{matrix}}}
a b ¯ c ¯ ∨ a ¯ b c ¯ ∨ a ¯ b ¯ c {\displaystyle {\begin{matrix}&a~{\bar {b}}~{\bar {c}}\\\lor &{\bar {a}}~b~{\bar {c}}\\\lor &{\bar {a}}~{\bar {b}}~c\end{matrix}}}
o d d l y m a n y o f a , b , c a r e t r u e . {\displaystyle {\begin{matrix}\mathrm {oddly~many~of} \\a,b,c\\\mathrm {are~true} .\end{matrix}}}
a + b + c {\displaystyle a+b+c} a b c ∨ a b ¯ c ¯ ∨ a ¯ b c ¯ ∨ a ¯ b ¯ c {\displaystyle {\begin{matrix}&a~b~c\\\lor &a~{\bar {b}}~{\bar {c}}\\\lor &{\bar {a}}~b~{\bar {c}}\\\lor &{\bar {a}}~{\bar {b}}~c\end{matrix}}}
p a r t i t i o n x i n t o a , b , c . g e n u s x c o m p r i s e s s p e c i e s a , b , c . {\displaystyle {\begin{matrix}\mathrm {partition} ~x\\\mathrm {into} ~a,b,c.\\[6pt]\mathrm {genus} ~x~\mathrm {comprises} \\\mathrm {species} ~a,b,c.\end{matrix}}}
x ¯ a ¯ b ¯ c ¯ ∨ x a b ¯ c ¯ ∨ x a ¯ b c ¯ ∨ x a ¯ b ¯ c {\displaystyle {\begin{matrix}&{\bar {x}}~{\bar {a}}~{\bar {b}}~{\bar {c}}\\\lor &x~a~{\bar {b}}~{\bar {c}}\\\lor &x~{\bar {a}}~b~{\bar {c}}\\\lor &x~{\bar {a}}~{\bar {b}}~c\end{matrix}}~}
a + b + c {\displaystyle a+b+c}
a b c ∨ a b ¯ c ¯ ∨ a ¯ b c ¯ ∨ a ¯ b ¯ c {\displaystyle {\begin{matrix}&a~b~c\\\lor &a~{\bar {b}}~{\bar {c}}\\\lor &{\bar {a}}~b~{\bar {c}}\\\lor &{\bar {a}}~{\bar {b}}~c\end{matrix}}}
x ′ x ~ ¬ x {\displaystyle {\begin{matrix}x'\\{\tilde {x}}\\\lnot x\end{matrix}}}
x implies y I f x then y {\displaystyle {\begin{matrix}x~{\text{implies}}~y\\\mathrm {If} ~x~{\text{then}}~y\end{matrix}}}
x not equal to y x exclusive or y {\displaystyle {\begin{matrix}x~{\text{not equal to}}~y\\x~{\text{exclusive or}}~y\end{matrix}}}
x ≠ y x + y {\displaystyle {\begin{matrix}x\neq y\\x+y\end{matrix}}}
x is equal to y x if and only if y {\displaystyle {\begin{matrix}x~{\text{is equal to}}~y\\x~{\text{if and only if}}~y\end{matrix}}}
x = y x ⇔ y {\displaystyle {\begin{matrix}x=y\\x\Leftrightarrow y\end{matrix}}}
Just one of x , y , z is false . {\displaystyle {\begin{matrix}{\text{Just one of}}\\x,y,z\\{\text{is false}}.\end{matrix}}}
x ′ y z ∨ x y ′ z ∨ x y z ′ {\displaystyle {\begin{array}{l}x'y~z~~~\lor \\x~y'z~~~\lor \\x~y~z'\end{array}}}
Just one of x , y , z is true . Partition all into x , y , z . {\displaystyle {\begin{matrix}{\text{Just one of}}\\x,y,z\\{\text{is true}}.\\[5pt]{\text{Partition all}}\\{\text{into}}~x,y,z.\end{matrix}}}
x y ′ z ′ ∨ x ′ y z ′ ∨ x ′ y ′ z {\displaystyle {\begin{array}{l}x~y'z'~~\lor \\x'y~z'~~\lor \\x'y'z\end{array}}}
(( x , y ), z ) ( x ,( y , z )) {\displaystyle {\begin{matrix}{\texttt {((}}x{\texttt {,}}y{\texttt {),}}z{\texttt {)}}\\&\\{\texttt {(}}x{\texttt {,(}}y{\texttt {,}}z{\texttt {))}}\end{matrix}}}
Oddly many of x , y , z are true . {\displaystyle {\begin{matrix}{\text{Oddly many of}}\\x,y,z\\{\text{are true}}.\end{matrix}}}
x + y + z x y z ∨ x y ′ z ′ ∨ x ′ y z ′ ∨ x ′ y ′ z {\displaystyle {\begin{array}{l}x+y+z\\[5pt]x~y~z~~~\lor \\x~y'z'~~\lor \\x'y~z'~~\lor \\x'y'z\end{array}}}
Partition w into x , y , z . Genus w comprises species x , y , z . {\displaystyle {\begin{matrix}{\text{Partition}}~w\\{\text{into}}~x,y,z.\\[5pt]{\text{Genus}}~w~{\text{comprises}}\\{\text{species}}~x,y,z.\end{matrix}}}
w ′ x ′ y ′ z ′ ∨ w x y ′ z ′ ∨ w x ′ y z ′ ∨ w x ′ y ′ z {\displaystyle {\begin{array}{l}w'x'y'z'~~\lor \\w~x~y'z'~~\lor \\w~x'y~z'~~\lor \\w~x'y'z\end{array}}}
x ′ y z ∨ x y ′ z ∨ x y z ′ {\displaystyle {\begin{matrix}x'y~z~&\lor \\x~y'z~&\lor \\x~y~z'&\end{matrix}}}
Just one of x , y , z is true . Partition all into x , y , z . {\displaystyle {\begin{matrix}{\text{Just one of}}\\x,y,z\\{\text{is true}}.\\&\\{\text{Partition all}}\\{\text{into}}~x,y,z.\end{matrix}}}
x y ′ z ′ ∨ x ′ y z ′ ∨ x ′ y ′ z {\displaystyle {\begin{matrix}x~y'z'&\lor \\x'y~z'&\lor \\x'y'z~&\end{matrix}}}
x + y + z {\displaystyle x+y+z}
x y z ∨ x y ′ z ′ ∨ x ′ y z ′ ∨ x ′ y ′ z {\displaystyle {\begin{matrix}x~y~z~&\lor \\x~y'z'&\lor \\x'y~z'&\lor \\x'y'z~&\end{matrix}}}
Partition w into x , y , z . Genus w comprises species x , y , z . {\displaystyle {\begin{matrix}{\text{Partition}}~w\\{\text{into}}~x,y,z.\\&\\{\text{Genus}}~w~{\text{comprises}}\\{\text{species}}~x,y,z.\end{matrix}}}
w ′ x ′ y ′ z ′ ∨ w x y ′ z ′ ∨ w x ′ y z ′ ∨ w x ′ y ′ z {\displaystyle {\begin{matrix}w'x'y'z'&\lor \\w~x~y'z'&\lor \\w~x'y~z'&\lor \\w~x'y'z~&\end{matrix}}}