'begin' 'comment' This is a simple example for the ``Jensen device'' ; 'procedure' jdev ( i, n, s, x ) ; 'begin' s := 0; 'for' i := 1 'step' 1 'until' n 'do' s := s + x; 'end'; 'integer' NN; NN := 100; 'begin' 'integer' i; 'real' sum, t1sum, t2sum; 'integer' 'array' arr [1:NN]; t1sum := t2sum := 0; 'for' i:=1 'step' 1 'until' NN 'do' 'begin' arr[i] := i; t1sum := t1sum + i; t2sum := t2sum + 1 / i 'end'; jdev (i, NN, sum, arr[i]); outstring (1, `#1: '); outreal (1, t1sum); outreal (1, sum); outstring (1, `\n'); jdev (i, NN, sum, 1 / arr[i]); outstring (1, `#2: '); outreal (1, t2sum); outreal (1, sum); outstring (1, `\n') 'end'; 'end'