HP 48gII Graphing, 50g Graphing ==(Logical Equality)

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.

Access:	…Å		(Åis the right-shift of the Wkey).
Flags:	Numerical Results (–3)
Input/Output:
		Level 2/Argument 1 Level 1/Argument 2			Level 1/Item 1
		z1	z2	→	z1 = z2
		z	'symb'	→	'z = symb'
		'symb'	z	→	'symb = z'
		'symb1'	'symb2'	→	'symb1 = symb2'
		y_unit	x	→	y_unit1 = x
		y_unit	x_unit	→	y_unit1 = x_unit
		'symb'	x_unit	→	'symb = x_unit'
		x_unit	'symb'	→	'x_unit = symb'
	DEFINE,
See also:		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:	!°TEST ==	( °is the left-shift of the Nkey).
Flags:	Numerical Results (–3)

3-302 Full Command and Function Reference