# (logical Equality) - HP 48gII Advanced User's Reference Manual

Graphing calculator.

Description: Equals Analytic Function: Returns an equation formed from the two arguments.
The equals sign equates two expressions such that the difference between them is zero.
In Symbolic Results mode, the result is an algebraic equation. In Numerical Results mode, the
result is the difference of the two arguments because = acts equivalent to –. This allows
expressions and equations to be used interchangeably as arguments for symbolic and numerical
rootfinders.
Common usage is ambiguous about some units of temperature. When ºC or ºF represents a
thermometer reading, then the temperature is a unit with an additive constant: 0 ºC = 273.15 K,
and 0ºF = 459.67ºR. But when ºC or ºF represents a difference in thermometer readings, then the
temperature is a unit with no additive constant: 1ºC=1 K and 1ºF = 1ºR.
The arithmetic operators +, –, %, %CH, and %T treat temperatures as differences, without any
additive constant. However, +, –, %CH, and %T require both arguments to be either absolute
(K and ºR), both ºC, or both ºF. No other combinations are allowed.
...Å
Access:
Flags:
Numerical Results (-3)
Input/Output:
DEFINE, EVAL, –
==

## (Logical Equality)

Type:
Function
Description: Logical Equality Function: Tests if two objects are equal.
The function == returns a true result (1) if the two objects are the same type and have the same
value, or a false result (0) otherwise. Lists and programs are considered to have the same values if
the objects they contain are identical. If one object is algebraic (or a name), and the other is a
number (real or complex) or an algebraic, == returns a symbolic comparison expression that can
be evaluated to return a test result. Note that == is used for comparisons, while = separates two
sides of an equation. If the imaginary part of a complex number is 0, it is ignored when the
complex number is compared to a real number.
For unit objects, the two objects must be dimensionally consistent and are converted to common
units for comparison. If you use simple temperature units, the calculator assumes the values
represent temperatures and not differences in temperatures. For compound temperature units,
the calculator assumes temperature units represent temperature differences. For more
information on using temperature units with arithmetic functions, refer to the entry for +.
Access:
Flags:
Numerical Results (-3)
3-224 Full Command and Function Reference
(Å is the right-shift of the Wkey).
Level 2/Argument 1
Level 1/Argument 2
z
1
z
'symb'
'symb
'
1
y_unit
y_unit
'symb'
x_unit
==
TEST
z
2
'symb'
z
'symb
'
2
x
x_unit
x_unit
'symb'
( °is the left-shift of the Nkey).
Level 1/Item 1
z
= z
1
2
'z = symb'
'symb = z'
'symb
= symb
'
1
2
y_unit
= x
1
y_unit
= x_unit
1
'symb = x_unit'
'x_unit = symb'