func real VAdd(A, B, C);        \Add two 2D vectors
real A, B, C;                   \A:= B + C
[A(0):= B(0) + C(0);            \VAdd(A, A, C) => A:= A + C
 A(1):= B(1) + C(1);
return A;
];

func real VSub(A, B, C);        \Subtract two 2D vectors
real A, B, C;                   \A:= B - C
[A(0):= B(0) - C(0);            \VSub(A, A, C) => A:= A - C
 A(1):= B(1) - C(1);
return A;
];

func real VMul(A, B, S);        \Multiply 2D vector by a scalar
real A, B, S;                   \A:= B * S
[A(0):= B(0) * S;               \VMul(A, A, S) => A:= A * S
 A(1):= B(1) * S;
return A;
];

func real VDiv(A, B, S);        \Divide 2D vector by a scalar
real A, B, S;                   \A:= B / S
[A(0):= B(0) / S;               \VDiv(A, A, S) => A:= A / S
 A(1):= B(1) / S;
return A;
];

proc VOut(Dev, A);              \Output a 2D vector number to specified device
int  Dev; real A;               \e.g: Format(1,1);  (-1.5, 0.3)
[ChOut(Dev, ^();
RlOut(Dev, A(0));
Text(Dev, ", ");
RlOut(Dev, A(1));
ChOut(Dev, ^));
];

proc Polar2Rect(@X, @Y, Ang, Dist);     \Return rectangular coordinates
real X, Y, Ang, Dist;
[X(0):= Dist*Cos(Ang);
 Y(0):= Dist*Sin(Ang);
];      \Polar2Rect

real V0(2), V1, V2, V3(2);
def  Pi = 3.14159265358979323846;
[Format(1, 1);
V1:= [5., 7.];
V2:= [2., 3.];
Polar2Rect(@V3(0), @V3(1), Pi/4., sqrt(2.));
Text(0, "V1 = ");  VOut(0, V1);  CrLf(0);
Text(0, "V2 = ");  VOut(0, V2);  CrLf(0);
Text(0, "V3 = ");  VOut(0, V3);  CrLf(0);
CrLf(0);
Text(0, "V1 + V2 = ");  VOut(0, VAdd(V0, V1, V2 ));  CrLf(0);
Text(0, "V1 - V2 = ");  VOut(0, VSub(V0, V1, V2 ));  CrLf(0);
Text(0, "V1 * 11 = ");  VOut(0, VMul(V0, V1, 11.));  CrLf(0);
Text(0, "11 * V2 = ");  VOut(0, VMul(V0, V2, 11.));  CrLf(0);
Text(0, "V1 / 2  = ");  VOut(0, VDiv(V0, V1, 2. ));  CrLf(0);
]