Supported Syntax and Expressions

This page serves as the complete formal reference for grammar, operators, functions, and validation rules accepted by Jupiter's expression parser. This syntax is shared across metrics, guard conditions, and parameter expressions.

---

Numerical Literals

• Decimal Notation: Use decimal digits with a period (.) as the fraction delimiter: 10, 0.5, 3.14159, .25.
• Prohibited Syntax:
  • Commas: 1,5 is rejected with an unexpected token error.
  • Scientific Notation: 1e-5 or 2.5E+3 are invalid. Write out full decimal values: 0.00001.

---

Identifiers

Places (#PlaceName)

• The # character prefixes references to Petri net places.
• In guard conditions, #Place evaluates the instantaneous integer token count in that place.
• In metrics, #Place without braces is automatically treated as $E{\text{#Place}}$ (time average).
• Examples: #Queue, #InService, #Slots.

Parameters

• Must begin with a letter or underscore (_), followed by letters, digits, or _: [a-zA-Z_][a-zA-Z0-9_]*.
• Valid examples: ARRIVAL_DELAY, NUM_WORKERS, rate_1.
• Do not use accents, hyphens, or special punctuation.

---

Arithmetic Operators

Operator	Description	Precedence	Associativity
- (unary)	Sign negation	1 (highest)	Right to left
*	Multiplication	2	Left to right
/	Division	2	Left to right
+	Addition	3	Left to right
-	Subtraction	3 (lowest)	Left to right

Parentheses ( ) have highest precedence and enforce evaluation order: (A + B) * C.

---

Relational and Comparison Operators

Used to construct boolean logic:

Operator	Meaning	Example
= or ==	Equality	#Worker = 0, #Mode == 1
!=	Inequality	#Queue != 0
<	Less than	#Queue < CAPACITY
<=	Less than or equal to	#Slots <= 0
>	Greater than	#Queue > 10
>=	Greater than or equal to	#Workers >= 2

---

Logical Operators

Used to combine boolean expressions:

Operator	Meaning	Example
NOT	Logical negation (inverts boolean value)	NOT (#Slots > 0)
AND	Logical conjunction (true if both are true)	(#Queue > 0) AND (#Worker = 0)
OR	Logical disjunction (true if at least one is true)	(#Error > 0) OR (#Timeout > 0)

Parenthesize comparison sub-expressions when combining with logical operators.

---

Conditional Expressions (IF ... THEN ... ELSE)

The ternary conditional operator selects values based on boolean logic:

IF <condition> THEN <value_if_true> ELSE <value_if_false>

• The ELSE clause is mandatory. Omitting ELSE causes a syntax error.
• Conditional clauses may be nested:

  IF A > 10 THEN 100 ELSE IF A > 5 THEN 50 ELSE 0

---

Built-in Mathematical Functions

Function	Arguments	Description	Example
abs(x)	1 number	Returns absolute value of $x$	abs(E{#QueueA} - E{#QueueB})
min(a, b)	2 numbers	Returns the lesser of $a$ and $b$	min(E{#Queue}, LIMIT)
max(a, b)	2 numbers	Returns the greater of $a$ and $b$	max(E{#Queue} - 5, 0)

---

Temporal Integration Operators (Metrics Only)

Operator	Scope	Description	Example
E{ ... }	Mathematical expression	Expected value / time average integrated over the simulation duration	E{#Queue}, E{#Queue + #InService}
P{ ... }	Boolean condition	Fraction of simulation time (between 0 and 1) during which the condition held true	P{#Slots = 0}, P{#Queue > 10}

---

Feature Availability and Equivalents

Desired Operation	Supported Natively?	Workaround in Jupiter
Exponentiation ($A^2$)	No	A * A
Modulo division	No	Not supported in current version
Square root	No	Not supported in current version
Scientific notation (1e-6)	No	Write full decimal: 0.000001
Percentage conversion	No	Multiply by 100: P{#Slots = 0} * 100
Comma decimal separator	No	Use period: 0.5