public MaskedLong not() {
		return fromMaskAndValue(msk, ~val);
	}
Compute the bitwise NOT

<p>
To handle unknown bits, the result is derived from the following truth table:

<pre>{@code
0 x 1 <= A (this)
1 x 0
}</pre>

@return the result.
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/app/plugin/assembler/sleigh/expr/MaskedLong.java