In my textbook (for digital circuits), there is the next notation for a matrix:
A matrix with n rows and m columns can be written as $A^{1:n}_{1:m}$
Since I'm new to matrices altogether, I'm struggling to understand what the "$1:$" is supposed to represent.
I tried to google it, but I don't even know what this notation is called - I cannot even find a notation without the number one with a colon, or any other number in the place of 1.
Answer
As the comments suggested - yes, notation $l:m$ means "from $l$ to $m$", therefore, $A^{1:n}_{1:m}$ means "matrix $A$ with rows from $1$ to $n$ and columns from $1$ to $m$."
Potentially wrong further explanation:
This makes sense when performing operations on matrices:
$C^{1:n}_{1:m} = A^{1:n}_{1:t} * B^{1:t}_{1:m}$, where $*$ is some operator. Then one element of the matrix is calculated as such:
$c^{i}_{j} = /(a^{i}_{1:t} * b^{1:t}_{j})$
This means the operation for one element $c$ is calculated by performing a row reduction on $a$ elements (in the $i$-th column) and a column reduction on the $b$ elements (in the $j$-th row).