BeginPackage["Iloczyn`"];

SpirographIn::usage = "Polecenie SpirographIn[r1,r2] liczy iloczyn skalarny miedzy dwoma wektorami";

SpirographOut::usage="Polecenie SpirographOut[r1,r2] liczy iloczyn wektorowy miedzy dwoma wektorami";

Begin["Iloczyn`Private`"];

Unprotect[SpirographIn,SpirographOut];

SpirographIn[R_,r_]:=Block[{},
    If[Not[VectorQ[R]],Message[SpirographIn::vector,R]];
    If[Not[VectorQ[r]],Message[SpirographIn::vector,r]];
    R.r]

SpirographOut[R_,r_]:=Block[{},
    If[Not[VectorQ[R]],Message[SpirographOut::vector,R]];
    If[Not[VectorQ[r]],Message[SpirographOut::vector,r]];
    Cross[R,r]]

Protect[SpirographIn,SpirographOut];

End[]


EndPackage[]
