Table 2.

The local phase portraits at the finite and infinite equilibrium points of the continuous piecewise differential systems (I)

Systems	Conditions	Finite equilibrium points	Infinite equilibrium points
(I)	(I-1): $\sigma <-2$	$P_{+}$(stable node)	$p_{+}$(saddle)
			$p_{-}$(unstable node)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)
	(I-2): $\sigma =-2$	$P_{+}$(stable node)	p(semi-hyperbolic saddle-node)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)
	(I-3): $-2<\sigma <0$	$P_{+}$(stable focus)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)
	(I-4): $\sigma =0$	$P_{+}$(center)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)
	(I-5): $0<\sigma <2$	$P_{+}$(unstable focus)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)
	(I-6): $\sigma =2$	$P_{+}$(unstable node)	p(semi-hyperbolic saddle-node)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)
	(I-7): $\sigma >2$	$P_{+}$(unstable node)	$p_{+}$(stable node)
			$p_{-}$(saddle)
		$P_{-}$(saddle)	$q_{+}$(stable node)
			$q_{-}$(unstable node)