E. Cobham Brewer 1810–1897. Dictionary of Phrase and Fable. 1898. 
 Diophan’tine Anal’ysis.  
Finding commensurate values of squares, cubes, triangles, etc.; or the sum of a given number of squares which is itself a square; or a certain number of squares, etc., which are in arithmetical progression. The following examples will give some idea of the theory:  1 
1. To find two whole numbers, the sum of whose squares is a square;  2 
2. To find three square numbers which are in arithmetical progression;  3 
3. To find a number from which two given squares being severally subtracted, each of the remainders is a square.  4 
Diophantus was an Alexandrian Greek (5th cent. A.D.)  5 


