5 (2c) Consider a subset of the plane R2, that is, SE P IR2| such that: P := (a, b ) and Q := (b, a) My P == ( and my Q = ( k + 1 # 0) SL P, Q = (x , y ) ER2 3k , IER A x = P1 + 191 k+ 1 A y = kp2 + 192 k+l My SL. ( ) . ( ) ( k + 1 # 0) = (x,y) ER2 3k, LEIR ( x = K ( )+LC k+l ( y= k ( ) +1( k+1 Decide if: StLn SL P, Q , that is the set SL P, Q is a straight line in the sense of the predicate StLn. Y N Pf W