let r be Element of REAL ; for p, q being Element of REAL 3
for f1, f2, f3, g1, g2, g3 being PartFunc of ,
for t being Real st p = (VFunc f1,f2,f3) . t & q = (VFunc g1,g2,g3) . t holds
( (r * p) <X> q = r * (p <X> q) & (r * p) <X> q = p <X> (r * q) )
let p, q be Element of REAL 3; for f1, f2, f3, g1, g2, g3 being PartFunc of ,
for t being Real st p = (VFunc f1,f2,f3) . t & q = (VFunc g1,g2,g3) . t holds
( (r * p) <X> q = r * (p <X> q) & (r * p) <X> q = p <X> (r * q) )
let f1, f2, f3, g1, g2, g3 be PartFunc of ,; for t being Real st p = (VFunc f1,f2,f3) . t & q = (VFunc g1,g2,g3) . t holds
( (r * p) <X> q = r * (p <X> q) & (r * p) <X> q = p <X> (r * q) )
let t be Real; ( p = (VFunc f1,f2,f3) . t & q = (VFunc g1,g2,g3) . t implies ( (r * p) <X> q = r * (p <X> q) & (r * p) <X> q = p <X> (r * q) ) )
assume A1:
( p = (VFunc f1,f2,f3) . t & q = (VFunc g1,g2,g3) . t )
; ( (r * p) <X> q = r * (p <X> q) & (r * p) <X> q = p <X> (r * q) )
A2: (r * p) <X> q =
|[(r * (f1 . t)),(r * (f2 . t)),(r * (f3 . t))]| <X> q
by A1, Th38
.=
|[(r * (f1 . t)),(r * (f2 . t)),(r * (f3 . t))]| <X> |[(g1 . t),(g2 . t),(g3 . t)]|
by A1, Def1
.=
|[(((r * (f2 . t)) * (g3 . t)) - ((r * (f3 . t)) * (g2 . t))),(((r * (f3 . t)) * (g1 . t)) - ((r * (f1 . t)) * (g3 . t))),(((r * (f1 . t)) * (g2 . t)) - ((r * (f2 . t)) * (g1 . t)))]|
by Lm11
;
A3: (r * p) <X> q =
|[(r * (((f2 . t) * (g3 . t)) - ((f3 . t) * (g2 . t)))),(r * (((f3 . t) * (g1 . t)) - ((f1 . t) * (g3 . t)))),(r * (((f1 . t) * (g2 . t)) - ((f2 . t) * (g1 . t))))]|
by A2
.=
r * |[(((f2 . t) * (g3 . t)) - ((f3 . t) * (g2 . t))),(((f3 . t) * (g1 . t)) - ((f1 . t) * (g3 . t))),(((f1 . t) * (g2 . t)) - ((f2 . t) * (g1 . t)))]|
by LmA8
.=
r * (p <X> q)
by A1, Th55
;
(r * p) <X> q =
|[(((f2 . t) * (r * (g3 . t))) - ((f3 . t) * (r * (g2 . t)))),(((f3 . t) * (r * (g1 . t))) - ((f1 . t) * (r * (g3 . t)))),(((f1 . t) * (r * (g2 . t))) - ((f2 . t) * (r * (g1 . t))))]|
by A2
.=
|[(f1 . t),(f2 . t),(f3 . t)]| <X> |[(r * (g1 . t)),(r * (g2 . t)),(r * (g3 . t))]|
by Lm11
.=
p <X> |[(r * (g1 . t)),(r * (g2 . t)),(r * (g3 . t))]|
by A1, Def1
.=
p <X> (r * q)
by A1, Th38
;
hence
( (r * p) <X> q = r * (p <X> q) & (r * p) <X> q = p <X> (r * q) )
by A3; verum