[racket] Latex Symbols

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Sun Aug 24 22:02:24 EDT 2014

There isn't built-in support for that, I'm sorry to say. You can use
unicode characters that have hats on them, which should be
straightforward, or you can implement a function that accepts and
returns picts and then draws a hat on top of the given pict to produce
the result pict. Below is a start on such a function. You'll need to
use the redex pict adjustment combinators to actually use this
function, tho, and how you do that depends on how your model is set


#lang racket
(require pict)

(define (wide-hat p)
  (define hat-h (* (pict-height p) .2))
  (define hat-w (pict-width p))
  (define (draw-hat dc dx y)
    (send dc draw-line
          dx (+ dy hat-h)
          (+ dx (/ hat-w 2)) dy)
    (send dc draw-line
          (+ dx (/ hat-w 2)) dy
          (+ dx hat-w) (+ dy hat-h)))
  (inset (refocus
           (dc draw-hat hat-w hat-h)
         0 hat-h 0 0))

(wide-hat (text "a"))
(wide-hat (text "a+b+c+d"))

On Sun, Aug 24, 2014 at 6:03 PM, Maria Jenkins <mkjxocai at gmail.com> wrote:
> Hello all,
> I am writing a paper and the implementation was done in redex.
> My question is when I render the semantics and state space is there a way to get a wide hat symbol to print out over some of the characters like in latex?
> Thank you!
> Maria
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