matrix invert _please help me about thats

[adnansojib]

                                                                                                                     

float sectdists[] = point(1, "sectdist", @id);
matrix xforms[] = point(1, "xform", @id);

foreach(int i; matrix xform; xforms){
    matrix xform_inv = invert(xform);         /// i have confusion how its work 
    vector local_P = @P*xform_inv;             ///also this multiply     

    if (local_P.z > sectdists){
        local_P = set(local_P.x, local_P.y, sectdists);
        @P = local_P * xform;
        @Cd = {1,0,0};
        }
    
    }

Edited May 4, 2019 by adnansojib
i didnt say for solution

[probiner]