A1 = 13.453756490109397
B1 = -7.386376112216931
A2 = -6.3
B2 = -11.31
A4: A1^(2) + A2^(2)
B4: B1^(2) + B2^(2)

Tool: OISEAU
Input: Hotel, Empire
Output: u

u = Vector(Hotel, Empire)

Tool: Vol d'oiseau (command Vold'oiseau)
Input: Hotel, Empire
Output: u

u = OISEAU(Hotel, Empire)