# TI-Basic 84 Programming/Test Conditions and Logical Operators

Nota Bene: The TI 83/84 uses any nonzero number to represent true (most often it is 1) and zero to represent false.

## Test Conditions

Test Conditions are used to compare different values and form the basis of Conditional Functions.

### Equal

=, TEST:TEST:1 returns true if two input values are equal and false if not equal.

#### Syntax

```:Value 1 = Value 2
```
• Where Value 1 and Value 2 are both variables of the same type.

#### Example

```PROGRAM:TEMP
:0→X
:If X=0
:Disp "True"
```
```prgmTEMP
True
```

### Not Equal

≠, TEST:TEST:2 returns true if two input values are not equal and false if they are equal.

See Equal

### Greater Than

>, TEST:TEST:3 returns true if first input value is larger than second input value and false if it is less than or equal.

See Equal

### Greater Than or Equal To

≥, TEST:TEST:4 returns true if the first input value is larger than or equal to the second value and false if it is greater than.

See Equal

### Less Than

<, TEST:TEST:5 returns true if the first input value is smaller than the second and returns false if it is greater than or equal to.

See Equal

### Less Than or Equal To

≤, TEST:TEST:6 returns true if the first input value is smaller than or equal to the second input value and returns false if it is greater than.

See Equal

## Logical Operators

Logical Operators help combine multiple boolean valued statements into one.

### And

In order for an "and" conditional function evaluate to true, both parts of the statement have to be true or else it returns false.

#### Syntax

and, TEST:LOGIC:1

```:Boolean 1  and  Boolean 2
```
• Where Boolean 1 and Boolean 2 are both expressions that can be evaluated to true or false.

#### Example

```PROGRAM:TEMP
:0→X
:1→Y
:If X=0  and  Y=1
:Disp "TRUE"
```
```prgmTEMP
TRUE
```

### Or

In order for an "or" conditional function to evaluate to true, at least one of the parts of the statement have to be true or else it returns false.

or, TEST:LOGIC:2

See And

#### XOr

In order for an "xor" conditional function to evaluate to true, exactly one of the values has to be true. If both of the values are true or false it evaluates to false.

#### Syntax and Example

xor, TEST:LOGIC:3

See And

### Not

The "not" operator is a little different from the others, it only takes one value and it evaluates to the opposite.

#### Syntax

not(, TEST:LOGIC:4

```:not(valueA)
```
• valueA can be almost anything. It can be a single number since numbers represent true and false, or it can be a boolean expression that evaluates to true or false.

#### Example

```PROGRAM:TEMP
:0→X
:If not(X≠0)
:Disp "X DOES NOT NOT EQUAL ZERO"
```
```prgmTEMP
X DOES NOT NOT EQUAL ZERO
```

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