\documentclass{article}

\newif\ifA\newif\ifNOTA
\newif\ifB\newif\ifNOTB

\def\OprNOT#1{%
  \csname \csname if#1\endcsname NOT#1fals\else NOT#1tru\fi e\endcsname
}

\newcommand\testtest{
  \ifA a true \else a false\fi 
  \quad
  \ifB b true \else b false\fi

  \OprNOT{A}\OprNOT{B}
  \ifNOTA not a true \else not a false\fi
  \quad
  \OprNOT{A}\OprNOT{B}
  \ifNOTB not b true \else not b false\fi

  AND:
   \ifA\ifB tttt\else ffff\fi\else ffff\fi

  OR:
   \ifNOTA\ifNOTB ffff\else tttt\fi\else tttt\fi
}

\begin{document}

NOW:

\bigskip

\Afalse\Bfalse
\testtest

\bigskip

\Atrue\Btrue
\testtest

\bigskip

\Atrue\Bfalse
\testtest

\bigskip

\Afalse\Btrue
\testtest

\end{document}