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FreeQ

FreeQ
yields True if no subexpression in expr matches form, and yields False otherwise.
FreeQ
tests only those parts of expr on levels specified by levelspec.
MORE INFORMATION
  • form can be a pattern.
  • FreeQ uses standard level specifications:
nlevels through n
Infinitylevels through Infinity
{n}level n only
{n1,n2}levels through
  • A positive level n consists of all parts of expr specified by n indices.
  • A negative level -n consists of all parts of expr with depth n.
  • Level consists of numbers, symbols and other objects that do not have subparts.
  • Level corresponds to the whole expression.
  • With the default option setting Heads->True, FreeQ looks at heads of expressions, and their parts.
EXAMPLESCLOSE ALL
Basic Examples   (2)
Test whether a list is free of :
FreeQ normally tests all levels in an expression:
Test whether a list is free of :
In[1]:=
Click for copyable input
Out[1]=
 
FreeQ normally tests all levels in an expression:
In[1]:=
Click for copyable input
Out[1]=
Scope   (1)
FreeQ works with patterns:
Applications   (2)
Define a function that factors out "constants":
Test which integrals are free of logarithms:
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