Concept of essence is a compound and definable concept

In Islamic philosophy, two phrases about concept/ meaning of essence are famous: concept of essence: 1) is the most general concept; 2) is vast, upper clear and undefinable. But the independent theory about the affair itself draws us to conclusion that essence (special essence or opposed the inexistence) is in the following of two general concepts: 1) reality meaning general (general essence), 2) real essence (against credit essence). In other words, special essence firstly is subgroup of general essence; secondly is subgroup of real essence. We can define the two mixture as follows: (general essence+ reality= real essence) + property of opposing inexistence= special essence. Therefore, special essence is compound of three affairs (general essence, reality and property of opposing inexistence. Hence, 1. Essence is not the most general concept; 2. Is not vast, upper clear but is secondary clear so is definable. But general essence which is not opposed to inexistence: 1. is the most general concept; 2. is vast, upper clear and undefinable.