for M being MidSp
for W being ATLAS of M
for a, b, c, d being Point of M
for x being Vector of W holds
( W . (a,a) = 0. W & ( W . (a,b) = 0. W implies a = b ) & W . (a,b) = - (W . (b,a)) & ( W . (a,b) = W . (c,d) implies W . (b,a) = W . (d,c) ) & ( for b being Point of M
for x being Vector of W ex a being Point of M st W . (a,b) = x ) & ( W . (b,a) = W . (c,a) implies b = c ) & ( a @ b = c implies W . (a,c) = W . (c,b) ) & ( W . (a,c) = W . (c,b) implies a @ b = c ) & ( a @ b = c @ d implies W . (a,d) = W . (c,b) ) & ( W . (a,d) = W . (c,b) implies a @ b = c @ d ) & ( W . (a,b) = x implies (a,x) . W = b ) & ( (a,x) . W = b implies W . (a,b) = x ) )