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Type::NonZero -- a type and a property representing ``unequal to zero''

Introduction

Type::NonZero is a type of objects unequal to zero. Type::NonZero is a property, too, which can be used in an assume call.

Call(s)

testtype(obj, Type::NonZero)
assume(x, Type::NonZero)
is(ex, Type::NonZero)

Parameters

obj - any MuPAD object
x - an identifier or one of the expressions Re(u) or Im(u) with an identifier u
ex - an arithmetical expression

Returns

see testtype, assume and is

Related Functions

testtype, is, assume, Type::Zero

Details

Example 1

Usage of Type::NonZero whith testtype:

>> testtype(1.0, Type::NonZero)
                                   TRUE

Since iszero(x) returns FALSE, the following call returns TRUE:

>> testtype(x, Type::NonZero)
                                   TRUE

Example 2

Usage of Type::NonZero whith assume and is:

>> is(x, Type::NonZero)
                                  UNKNOWN

Assumption: x is Type::NonZero:

>> assume(x, Type::NonZero):
   is(x, Type::NonZero)
                                   TRUE

The same again:

>> assume(x <> 0):
   is(x <> 0)
                                   TRUE

The difference between testtype and is:

>> delete x:
   is(x, Type::NonZero), testtype(x, Type::NonZero)
                               UNKNOWN, TRUE

x could be zero:

>> assume(x >= 0):
   is(x, Type::NonZero), testtype(x, Type::NonZero)
                               UNKNOWN, TRUE
>> delete x:

Changes




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