lispdoc - results for 1+ 

plus
 
 Mentioned in:
HyperSpec - 2.4.8.17 Sharpsign Plus
(1+ number)
Function: Return NUMBER + 1.
Example:
(defun tomorrow (parsed-values)
  (set-current-value parsed-values :date t :zone
   t)
  (setf (decoded-time-day parsed-values)
          (1+ (decoded-time-day parsed-values))))
Mentioned in:
CLtL2 - 12.4. Arithmetic Operations
CLtL2 - 2.3. Symbols
HyperSpec - Function 1+, 1-
On Lisp - An ATN Compiler
On Lisp - Avoiding Capture by Prior Evaluation
On Lisp - Avoiding Capture with Gensyms
On Lisp - Avoiding Capture with Packages
On Lisp - Building Functions
On Lisp - Composing Functions
On Lisp - Continuation-Passing Macros
On Lisp - Extending Lisp
On Lisp - Functional Design
On Lisp - Local Functions
On Lisp - Macro Argument Capture
On Lisp - Macros as Programs
On Lisp - Need for Macros
On Lisp - Non-functional Expanders
On Lisp - Number of Evaluations
On Lisp - Recursion on Cdrs
On Lisp - Recursion on Cdrs (Macros Returning Functions)
On Lisp - Scheme Continuations
On Lisp - The Process Abstraction
On Lisp - When Capture Occurs
On Lisp - When Nothing Else Will Do
PCL - basic math

By Bill Moorier