Need to remove duplicate slab on laye if they have the same pipe of DDNAME

You can use this macros standing on LAYE

!aSlabs = !!CollectAllFor('SLAB', '', ce)
!aUniqueDdnames = ARRAY()

do !slab values !aSlabs
	if(!aUniqueDdnames.FindFirst(!slab.Ddname).Unset().Not()) then
		$p [dublicat found] = $!slab
		$!slab
		delete slab
		handle none
			$p [dublicat deleted]
		elsehandle any
			$p [dublicat can not be deleted]
		endhandle	
	else
		!aUniqueDdnames.Append(!slab.Ddname)
	endif
enddo

You can use this macros standing on LAYE

!aSlabs = !!CollectAllFor('SLAB', '', ce)
!aUniqueDdnames = ARRAY()

do !slab values !aSlabs
	if(!aUniqueDdnames.FindFirst(!slab.Ddname).Unset().Not()) then
		$p [dublicat found] = $!slab
		$!slab
		delete slab
		handle none
			$p [dublicat deleted]
		elsehandle any
			$p [dublicat can not be deleted]
		endhandle	
	else
		!aUniqueDdnames.Append(!slab.Ddname)
	endif
enddo

Hi Emin I tried with your code but nothing happen 

Sorry I misunderstood your task. Please test this macro

!aSlabs = !!CollectAllFor('SLAB', '', ce)
!aUniqueDdnames = ARRAY()

do !slab values !aSlabs
	if(!aUniqueDdnames.FindFirst(Pipe of $!slab.Ddname).Unset().Not()) then
		$p [dublicat found] = $!slab
		!pipe = Pipe of $!slab.Ddname
		$p [Pipe] = $!pipe
		$!slab
		delete slab
		handle none
			$p [dublicat deleted]
		elsehandle any
			$p [dublicat can not be deleted]
		endhandle	
	else
		!aUniqueDdnames.Append(Pipe of $!slab.Ddname)
	endif
	
enddo

It works so good, thank you Emin