In mathematics, particularly in linear algebra,
a skew-symmetric matrix (also known as an antisymmetric or antimetric) is a square matrix
**
A
**
which is transposed
and negative.
This means that it satisfies the equation
A = −A
^{
T
}
.
If the entry in the i-th row and j-th column is a
_{
ij
}
, i.e.
A = (a
_{
ij
}
)
then the symmetric condition becomes
a
_{
ij
}
= −a
_{
ji
}
.

You should determine whether the specified square matrix is skew-symmetric or not.

You can find more details on Skew-symmetric matrices on its Wikipedia page.

**
Input:
**
A square matrix as a list of lists with integers.

**
Output:
**
If the matrix is skew-symmetric or not as a boolean.

**
Example:
**

checkio([ [ 0, 1, 2], [-1, 0, 1], [-2, -1, 0]]) == True checkio([ [ 0, 1, 2], [-1, 1, 1], [-2, -1, 0]]) == False checkio([ [ 0, 1, 2], [-1, 0, 1], [-3, -1, 0]]) == False

**
How it is used:
**
Skew-symmetric matrices can be useful for the cross product, mathematical operations which are used for the calculation of force movements.
Matrixes are the basis of linear algebra and vector graphics.

**
Precondition:
**
0 < N < 5

CheckiO Extensions allow you to use local files to solve missions. More info in a blog post.

In order to install CheckiO client you'll need installed Python (version at least 3.8)

Install CheckiO Client first:

pip3 install checkio_client

Configure your tool

checkio --domain=py config --key=

Sync solutions into your local folder

checkio sync

(in beta testing) Launch local server so your browser can use it and sync solution between local file end extension on the fly. (doesn't work for safari)

checkio serv -d

Alternatevly, you can install Chrome extension or FF addon

checkio install-plugin

checkio install-plugin --ff

checkio install-plugin --chromium

Read more here about other functionality that the checkio client provides. Feel free to submit an issue in case of any difficulties.