First
First[expr]
returns the first part of expr
.
Attributes[First] := {Protected}
Simple examples
In[1]:= First[{1, 5, 6}] Out[1]= 1
In[2]:= First[a + b] Out[2]= a
First[expr]
returns the first part of expr
.
Attributes[First] := {Protected}
In[1]:= First[{1, 5, 6}] Out[1]= 1
In[2]:= First[a + b] Out[2]= a