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Re: Evaluation question

Szabolcs Horvát wrote:
> It seems that Rule and RuleDelayed are "evaluated to themselves":
> In[1]:= Trace[1->2+3]
> Out[1]= {{2+3,5},1->5,1->5}
> In[2]:= Attributes[f]=Attributes[Rule]
> Out[2]= {Protected,SequenceHold}
> In[3]:= Trace[f[1,2+3]]
> Out[3]= {{2+3,5},f[1,5]}

Block[] can free Rule from this special behaviour:

In[1]:= Block[{Rule},1->Unevaluated[2+3]]//Trace



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