Question: pls help me: What's wrong that led to the error message?

i was trying to familiarize with maple 13 but encountered this. pls how may i go out from here?

> with(Student[NumericalAnalysis]);
> DE1 := d*y(t)/dt = y(t)-t^2+1;
                           d y(t)           2   
                           ------ = y(t) - t  + 1
                             dt                 
> InitialVaueProblem(DE1, y(0) = .5, t = 3);
                          /d y(t)           2                       \
        InitialVaueProblem|------ = y(t) - t  + 1, y(0) = 0.5, t = 3|
                          \  dt                                     /
> InitialValueProblem(DE1, y(0) = .5, t = 3, output = Error);
Error, (in Student:-NumericalAnalysis:-InitialValueProblem) the ODE must be explicitly given in the form diff(y(t), t) = f(t, y)
>