26996 contract law/ performance impossible/ reinstatement of parties contract law form of contract Federal supreme court of Ethiopia cassation decisions contract of sale volume 7 reinstatement of parties ውል የተደረገበት ጉዳይ ሊፈፀም የማይችል ሆኖ በተገኘ ጊዜ ተዋዋይ ወገኖችን ወደ ነበሩበት ቦታ የመመለስ ውጤት ያለው ስለመሆኑ የፍ/ብ/ህ/ቁ. 1715, 1815 Cassation Decision no. 26996