Under the hypothesis that 
and 
, where 
and 
denote arbitrary matrices whose columns form a basis of 
and 
respectively, the function 
returns the (unstructured) matrix 
for which the following matrix inequality is satisifed:
![\[A^TXB+B^TX^TA+P\prec0.\]](https://usercontent.one/wp/www.iqclab.eu/wp-content/ql-cache/quicklatex.com-d8363a00cc9237d823161baa446fa567_l3.png?media=1702023987 "Rendered by QuickLaTeX.com")
Gateway for robustness analysis and control design