:: deftheorem Def6 defines (#) MESFUNC1:def 6 :
for C being non empty set
for f being b₁ -defined ExtREAL -valued Function
for r being Real
for b₄ being PartFunc of C,ExtREAL holds
( b₄ = r (#) f iff ( dom b₄ = dom f & ( for c being Element of C st c in dom b₄ holds
b₄ . c = r * (f . c) ) ) );