!=

$$\text{Result}_i = \begin{cases} \text{null} & \text{if } A_i \text{ or } B_i \text{ is null} \\ \text{true} & \text{if } A_i \neq B_i \\ \text{false} & \text{if } A_i = B_i \end{cases}$$

The Not Equal module performs element-wise inequality comparison between two data series, returning true when values differ and false when they match.

Value A	Value B	A ≠ B
100	100	false
100	101	true
50.5	50.5	false
-10	10	true

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Missing Data

If either input is missing (null) at a position — a data gap or a closed-market day — the comparison at that position is null. The module never fabricates a boolean: a one-sided gap is not a "values changed" signal, and two simultaneous gaps are not "values match" — both are simply unknown.

Value A	Value B	A ≠ B
100	null	null
null	100	null
null	null	null

NEQ has no mathematically undefined cases beyond missing data: inequality is defined for every pair of real numbers, including infinities.

In live execution the module returns exactly one datapoint — the newest position — which is null when it cannot be determined.

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Floating-Point Precision

⚠️ Critical: Floating-point numbers may have tiny precision differences that cause unexpected results.

Expression	Expected	Actual Result
0.1 + 0.2 != 0.3	false	true

Why? Computers store decimals in binary, which can't perfectly represent all fractions. The value 0.1 + 0.2 is stored as 0.30000000000000004, making it technically "not equal" to 0.3.

Implication: NEQ may return true for values that are mathematically equal but differ due to floating-point representation.

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Input Alignment

When inputs have different lengths or frequencies, Systemic automatically aligns them:

Scenario	Behavior
Different lengths	Shorter series is padded by repeating its last value
Different frequencies	Lower-frequency series is upsampled to match
Constant vs series	Constant is broadcast to all time points

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Practical Example

Change detection: Compare the current value to the previous value to detect when a signal has changed state. NEQ outputs true at the moment of transition. A data gap on either side produces null, never a false "changed" signal.

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Related Modules

• EQ — Equality comparison (opposite of NEQ)
• GTR / LST — Greater than / Less than comparisons
• NOT — Invert boolean results