An irreducible Heegaard diagram of the real projective 3-space<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="$P^3$"><mml:mrow><mml:msup><mml:mi>p</mml:mi><mml:mn>3</mml:mn></mml:msup></mml:mrow></mml:math>
International journal of mathematics and mathematical sciences