question: public ShapeTileSimplex remove_border_line ( int p_no ) { if ( p_no < 0 || p_no >= lines_size ( ) ) { return this ; } ArrayList < PlaLineInt > new_arr = new ArrayList < PlaLineInt > ( lines_size ( ) ) ; new_arr . addAll ( lines_list ) ; new_arr . remove ( p_no ) ; return new ShapeTileSimplex ( new_arr ) ; }
target:  Enlarges the simplex by removing the edge line with index p_no. The result simplex may be unbounded.