Adjunction inequality for a simple J-holomorphic sphere
= Adjunction inequality for a simple J-holomorphic sphere
{title2=$c_1(A)\leq A^2+2$}
The singular-curve adjunction formula in a <symplectic manifold> of real dimension four gives $c_1(A)=A^2+2-2\delta$ for a <simple J-holomorphic sphere>, with a nonnegative singularity count $\delta$. Hence the displayed inequality holds. This is the version needed when the sphere need not be embedded.