Testing ANSWER cmd

[compsystems]

Hello, the following statements Written on CAS history

print("test ANS cmd");
id0:=0+1;
print("ans1: "+Ans); // ans1: 1
id0:=1+1;
print("ans2: "+Ans); // ans2: 2
id0:=2+1;
print("ans3: "+Ans); // ans3: 3

show in the terminal view

test ANS cmd
ans1: 1
ans2: 2
ans3: 3

But within a program

PHP Code:

#cas
    anscmd():=
    begin
                       print;  
        print("test ANS cmd");
        id0:=0+1;
        print("ans1: "+Ans); // ans1: 1
        id0:=1+1;
        print("ans2: "+Ans); // ans2: 2
        id0:=2+1;
        print("ans3: "+Ans); // ans3: 3
#end 


test ANS cmd
ans1: 0
ans2: 0
ans3: 0

Why?

The following CAS code Requires storing each statement in an identifier, and you can not use 'Ans' Cmd =(

PHP Code:

#cas
  script1():=
  begin
    local eq1, eq2, sol, answer;
      print;
    purge(x,y);
      print("Find the dimensions of a rectangle whose area is 45 and its perimeter 28");
    print("METHOD 1 (Algebraic solution, stepwise)");
        print("Let x = long, y = width");
   print("");

        print("The equations are:");    
    eq1:=x*y=45;    
    print("eq1: "+eq1); 
    eq2:=2x+2y=28; 
    print("eq2: "+eq2); 

    print("");
    answer:=factor(eq2); // -> (2*(x+y)) = 28
    print("factor(eq2): "+answer);

    print("");
    answer:=answer/2; // ->(2*(x+y)/2) = 14
    print("Ans/2: "+answer);
    answer:=simplify(answer); // -> (x+y) = 14
    print("simplify(Ans): "+answer);

    print("");
    sol:= y=solve(answer,y)[1]; //  y = (-x+14)
    print("sol(Ans,y): "+sol);

    print("");
    //answer:= (eq1|sol);
    answer:=subst(eq1,sol); //  -> (x*(-x+14)) = 45
    print("subst(eq1,answer): "+answer);
    answer:=simplify(answer); // -> (-x^2+14*x) = 45
    print("simplify(Ans): "+answer);

    print("");
    sol:=solve(answer,x); // -> {5,9}
    print("sol(Ans,x): x1,2="+sol);

    print("");
    print("test solutions");
    answer:=(eq1|{x=sol[1], y=sol[2]});
    print("eq1: "+answer);
    answer:=evalBool(answer,'=','==');
    print("eq1: "+answer);

    print("");
    answer:=(eq2|{x=sol[1], y=sol[2]});
    print("eq2: "+answer);
    answer:=evalBool(answer,'=','==');
    print("eq2: "+answer);
    return "Done";
  end;
#end

#cas
  evalBool( expr1, str1, str2 ):=
  begin
   return( ifte( subst(expr1, str1, str2 ), "TRUE", "FALSE") );
  end;
#end 


[KeithB]

I think ANS is a keyboard only thing that is there for convenience. It does not work on my HP71B, either, though that has a much clearer demarcation between "BASIC mode" and "CALC mode".

Though, I really like the () notation to get ans into an equation.