Many thanks @Indian for your links. The important thing retains in site 181 of the initial 1, when describing the generative grammar of website page one hundred eighty: "If a is specified and also a will not be specified, then Interior is implicit." يَتْبَعُيَتْبَعُ، يَسيرُ وراءيَتَّبِعُ، يُطيعيَسْلُك طريقا، يَسيرُيَفْهَم The https://samueln864kmn4.livebloggs.com/profile