Is this line of code valid and using correct Solidity syntax?

Question

(Language: Solidity | Version: Any)

Is this line of code valid and using correct Solidity syntax?

if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;

I'm new to solidity, and I'm experimenting with smart contract in forked chains. I've came across this line and doesn't know if this line of code is using valid solidity syntax.