1. A computing method for a computing system containing a user program system executing a user program and a library program system executing library programs to be used in the user program, said method comprising: the first transfer step of the user program system transferring process-target data which will be subjected to computation to the library program system; the second transfer step of the user program system receiving, from the library program system, process-result data representing results of the computation on the process-target data; and the computation instruction step and the computing step carried out between, and independently from, the first and second transfer steps, wherein: in the computation instruction step, the user program system instructs the library program system on content of the computation by means of a character string; and in the computing step, the library program system analyzes the character string to determine types of library programs to be used in the computation and an execution sequence of those library programs and executes the determined library programs in the determined execution sequence to carry out the computation on the process-target data.