Step-by-step programs in CAS

[compsystems]

Hello, I'm trying the following code (Step-by-step), but I see something strange in the output, please run the following program

PHP Code:

#cas
    testInequality1():=
    begin
     local expr0;
     print;

     print("step1:");
     expr0 := '(3*x^2-2*x-2) < (2*x^2-3*x+4)';
     //expr0 :=  (3*x^2-2*x-2) < (2*x^2-3*x+4);
     print(string(expr0)); 
     print("");

     print("step2: +(-2*x^2)");
     expr0 := expr0 + -2*x^2;
     print(string(expr0)); 
     expr0 := simplify(expr0); // Requires a sentence more, of simplification.
     print("simplify → " +expr0);
     print("");

     print("step3: +(3*x)");
     expr0 := expr0 + 3*x;
     print(string(expr0)); 
     expr0 := simplify(expr0); 
     print("simplify → "+expr0);
     print("");

     print("step4: +(-4)");
     expr0 := expr0 + -4;
     print(string(expr0)); 
     expr0 := simplify(expr0); 
     print("simplify → "+expr0);
     print("");
#end 


testInequality();

[
expr0: (--­4+4)>(x^2+x--­4-2)
left: --­4+4
right: x^2+x--­4-2
]

This is expected
[0>(x^2+x-6), 0, x^2+x-6]

[Han]

(01-10-2017 05:43 PM)compsystems Wrote:  Hello, I'm trying the following code (Step-by-step), but I see something strange in the output, please run the following program

PHP Code:

#cas
    testInequality():=
    begin
     local expr0;
     print("");
     expr0 := '(3*x^2-2*x-2) < (2*x^2-3*x+4)';
     //expr0 := (3*x^2-2*x-2) < (2*x^2-3*x+4);
     print("step1: " + expr0);

     expr0 := expr0  -2*x^2; 
     print("step2: " + expr0); expr0 := simplify(expr0); print("simplify ⇨ "+expr0);

     expr0 := expr0 + 3*x;
     print("step3: " + expr0); expr0 := simplify(expr0); print("simplify ⇨ "+expr0);

     expr0 := expr0  -­4;
     print("step4: " + expr0); expr0 := simplify(expr0); print("simplify ⇨ "+expr0);
     //return expr0;
     return [ expr0, left(expr0), right(expr0) ];
    end;
#end 


testInequality();

[
expr0: (--­4+4)>(x^2+x--­4-2) ?
left: --­4+4 ?
right: x^2+x--­4-2 ?
]

This is expected
[0>(x^2+x-6), 0, x^2+x-6]

When I copied your code, the "-" symbol in front of the 4 (in "step 4") was translated to two dashes: --4. Perhaps your editor is not using the correct symbol for subtraction.

[compsystems]

Thanks Han, (Updated above code), The problem was that when porting a code from ti68k, which uses the character #173 (-) as a change of sign, That is not the change of sign in the hp-prime

PHP Code:

// ti68k
inequali()
Prgm
 Local expr0
 ClrIO
 Disp "step1: "
 3*x^2-2*x-2 < 2*x^2-3*x+4 → expr0
 Disp expr0

 Disp "step2: +(-­2*x^2)"
 expr0 + ­2*x^2 → expr0
 Disp expr0

 Disp "step3: +3*x"
 expr0 + 3*x → expr0
 Disp expr0

 Disp "step4: +(-­4)": Pause
 expr0 + -­4 → expr0
 Disp expr0
EndPrgm