Mathematica is to its core a fundamentally extensible system, in which efficient, modular, reusable packages of any size can readily be created. Mathematica's symbolic ...
ClearAttributes[s, attr] removes attr from the list of attributes of the symbol s.
FullDefinition[symbol] prints as the definitions given for symbol, and all symbols on which these depend.
Definition[symbol] prints as the definitions given for a symbol.
ContentSelectable is an option to constructs such as Inset, Graphics, and GraphicsGroup that specifies whether and how content within them should be selectable.
Evaluate[expr] causes expr to be evaluated even if it appears as the argument of a function whose attributes specify that it should be held unevaluated.
HoldAll
(Built-in Mathematica Symbol) HoldAll is an attribute which specifies that all arguments to a function are to be maintained in an unevaluated form.
Clear
(Built-in Mathematica Symbol) Clear[symbol_1, symbol_2, ...] clears values and definitions for the symbol_i. Clear["form_1", "form_2", ...] clears values and definitions for all symbols whose names match ...
HoldFirst is an attribute which specifies that the first argument to a function is to be maintained in an unevaluated form.
Information[symbol] prints information about a symbol.