*! version 1.0.0  18Jan93 Royston; STB-11 sg1.4
*! republished STB-12 sg1.5
program define nlexp2a
	version 3.0
        if "`1'"=="?" {
                local depv "$S_E_depv"
                nlexp3 ? "`2'"
                mac def b1 $b0
                mac def S_2 "2-parameter asymptotic regression, `depv'=b1*(1-b2^`2')"
                mac def S_1 "b1 b2"
                exit
        }
        replace `1'=$b1*(1-$b2^`2')
end