Type and property representing negative numbers
This functionality does not run in MATLAB.
testtype(obj
, Type::Negative) assume(x
, Type::Negative) is(ex
, Type::Negative)
Type::Negative
represents negative numbers. Type::Negative
is
a property, too, which can be used in an assume
call.
The call testtype(obj, Type::Negative)
checks,
whether obj
is a negative real number and returns TRUE
, if
it holds, otherwise FALSE
.
testtype
only
performs a syntactical test identifying MuPAD^{®} objects of type DOM_INT
, DOM_RAT
and DOM_FLOAT
and
checks, if bool(obj < 0)
holds. This does not
include arithmetical expressions such as exp(1)
,
which are not identified as of type Type::Negative
.
The call assume(x, Type::Negative)
marks
the identifier x
as a negative real number.
The call is(ex, Type::Negative)
derives,
whether the expression ex
is a negative real number
(or this property can be derived).
This type represents a property that can be used in assume
and is
.
Instead of Type::Negative
the assumption
can also be assume(x < 0)
.
The following numbers are of type Type::Negative
:
testtype(2, Type::Negative), testtype(3/4, Type::Negative), testtype(0.123, Type::Negative), testtype(1, Type::Negative), testtype(1.02, Type::Negative)
The following expressions are exact representations of negative
numbers, but syntactically they are not of Type::Negative
:
testtype(exp(1), Type::Negative), testtype(PI^2  5, Type::Negative), testtype(sin(2), Type::Negative)
Assume an identifier is negative:
assume(x, Type::Negative): is(x, Type::Negative)
This is equal to:
assume(x < 0): is(x < 0)
Also negative numbers are real:
assume(x, Type::Negative): is(x, Type::Real)
However, real numbers can be negative or not:
assume(x, Type::Real): is(x, Type::Negative)
delete x:

Any MuPAD object 

An identifier or a mathematical expression containing identifiers 
