>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
		>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
		>>    modules name< Xt		>>
		>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
		>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Xt:
	
>----------------------->------------------------------------------------------>
 	1		>	Xt=1     pre is spiking			(1)    >
 			>	   0     pre is not spiking		       >
 			>						       >
>----------------------->------------------------------------------------------>
>	2		>	Xt=TR    pre is spiking			(2)    >
>			>	   0     pre is not spiking		       >
>			>						       >
>----------------------->------------------------------------------------------>
>	3		>	Xt=PSM   pre is spiking			(3)    >
>			>	   0     pre is not spiking		       >
>			>						       >
>----------------------->------------------------------------------------------>
>	4		>	Xt=TR x PSM    pre is spiking		(4)    >
>			>	   0           pre is not spiking	       >
>			>						       >
>----------------------->------------------------------------------------------>

		>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
PSM:		> 	Postsynaptic depression				>
		>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
		
>----------------------->------------------------------------------------------>
>			>						       >
>	1		>		  +--				       >
>    -0.04   >-.04 ud< 	>		  | -PSM/ud	   pre is 	       >
>     1.0     >1.0 ur<	>		  |		   spiking	       >
>			>	dPSM/dt= < 				(1)    >
>			>		  | 				       >
>			>		  | (1 - PSM)/ur    pre is 	       >
>			>		  +--		   not spiking	       >
>----------------------->------------------------------------------------------>

END: