reserve f,f1,f2,g for PartFunc of REAL,REAL;
reserve A for non empty closed_interval Subset of REAL;
reserve p,r,x,x0 for Real;
reserve n for Element of NAT;
reserve Z for open Subset of REAL;

theorem Th17:
  sinh.1 = (number_e^2 - 1)/(2*number_e)
proof
  sinh.1=(number_e - exp_R(-1))/2 by IRRAT_1:def 7,SIN_COS2:def 1
    .=(number_e/1 - 1/number_e)/2 by IRRAT_1:def 7,TAYLOR_1:4
    .=((number_e * number_e)/(1*number_e) - 1/number_e)/2 by TAYLOR_1:11
,XCMPLX_1:91
    .=((number_e)^2/number_e - 1/number_e)/2
    .=(number_e^2 - 1)/number_e/2 by XCMPLX_1:120
    .=(number_e^2 - 1)/(2*number_e) by XCMPLX_1:78;
  hence thesis;
end;
