^
A caret means superscript.
X^Y
X with a superscript Y
,
A comma is used to separate items in a list.
X,Y
List with X and Y as elements
#
A hashtag signals the title header in the Markdown file.
# Title123
Has “Title123” as model title
##
A double hashtag signals a new section in the Markdown file.
## Section123
Has “Section123” as a section name
###
A triple hashtag is a comment line in the Markdown file.
### Comment123
Has “Comment123” as a comment
{ }
Curly brackets are specification of exact values for a variable.
X{1}
X is a scalar with value of 1

Hypen is an undirected causal edge between two variables.
XY
Undirected causal edge between X and Y
( )
Parentheses are used to bound other expressions.
X^(Y_2)
X with a superscript that is Y with a subscript 2
[ ]
Rectangular brackets define the dimensionality, or state space, of a variable.
X[2,3]
X is a matrix with dimensions (2,3)
=
The equals sign declares the two side of the = to be equal.
X=5
Sets the variable X to value of 5
>
The greater than symbol represents a directed causal edge between two variables.
X>Y
Unidirectional causal edge from X to Y
_
Underscore means subscript.
X_2
X with a subscript 2