let V be ComplexLinearSpace; :: thesis: for v being VECTOR of V
for W being Subspace of V
for w being VECTOR of W st w = v holds
- v = - w

let v be VECTOR of V; :: thesis: for W being Subspace of V
for w being VECTOR of W st w = v holds
- v = - w

let W be Subspace of V; :: thesis: for w being VECTOR of W st w = v holds
- v = - w

let w be VECTOR of W; :: thesis: ( w = v implies - v = - w )
assume A1: w = v ; :: thesis: - v = - w
( - v = (- 1r) * v & - w = (- 1r) * w ) by Th3;
hence - v = - w by A1, Th33; :: thesis: verum