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AlloyTools / org.alloytools.alloy

Alloy is a language for describing structures and a tool for exploring them. It has been used in a wide range of applications from finding holes in security mechanisms to designing telephone switching networks. This repository contains the code for the tool.
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Wrong typechecking of local let #181

Closed grayswandyr closed 1 year ago

grayswandyr commented 2 years ago

The typing rule for the let construct seems bogus:

sig S {}

one sig e extends S {}

sig T {}

one sig f extends T {}

// "redundancy warning" on f, as expected
run p { some x: S | x = (some univ implies e else f) } 

// no warning, contrary to expectation
run q { some x: S | let d = (some univ implies e else f) | x = d }
grayswandyr commented 1 year ago

Typing of let addressed in #173