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PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
D. — THE CASE OF A STATIONARY PROCESS 
General Formulation 
140. In the case of a stationary process, we have 
(140-1) 
~ 
— nN 
and the preceding formulae simplify considerably. 
From relation (131-2) we have then 
(140-2) 
5(0)Ra = p(0)R, 
so that 
(140-3) 
/&(e) R, d6=/"s(6)R. de 
whence, from relations (111-3) and (111-4) 
(140-4) 
R.—R. 
C11] Allais - pag. 70