incorrect names in parameter file causes crashes

[ozgurakgun]

Originally reported by: wetterj (Bitbucket: wetterj, GitHub: wetterj)

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essence:

language Essence 1.3

given n : int(1..)

letting Range be domain int(1..n)

given f : function (total) Range --> int(1..)

find x : int(1..n)

param:

letting n be 2
letting F be function (1 --> 1, 2 --> 2)

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• Bitbucket: https://bitbucket.org/stacs_cp/conjure-private/issue/22

[ozgurakgun]

Original comment by Özgür Akgün (Bitbucket: ozgurakgun, GitHub: ozgurakgun):

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fixes #22 -- check missing and extra lettings in the parameter file