Augmentation Transformation Sample Clauses

Augmentation Transformation. ‌ Next, we introduce algorithms for translating a model with compound, selection, loop, etc. statements into a model with only variable declaration and expression 13 ▇▇▇▇://▇▇▇▇.▇▇▇▇.▇▇/bip2nusmv statements. We first describe Algorithm 2, which translates a single transition with an arbitrary statement into a set of states and internal transitions with only variable declaration, expression, and return statements. Then, we describe Algorithm 3, which translates an entire model with the help of Algorithm 2. Our augmentation algorithms are based on the small-step operational semantics of our supported Solidity Statements provided in Appendix A.3. Algorithm 2, called AugmentStatement, takes as input a Solidity statement, an origin, destination, and return state, and it creates a set of states and ▇▇▇▇- sitions that implement the input statement using only variable declaration, ex- pression, and return statements as actions. Note that before invoking this al- gorithm, Algorithm 3 removes the original transition between the origin and destination states; hence, this algorithm creates all transitions (and states) from scratch. If the statement is a variable declaration, event, or expression statement, then the algorithm simply creates a transition from the origin to the destina- tion state without any guards and having the statement as an action. If the statement is a return statement, then it creates a transition from the origin to the return state. Note that the return state is preserved by all recursive calls to AugmentStatement, and it is initialized with the destination of the original transition by Algorithm 3. If the statement is a compound, selection, or loop statement, Algorithm 2 creates a set of states and transitions. For a compound statement (i.e., list of statements), the algorithm creates a set of new states, each of which corre- sponds to the execution stage after an inner statement (except for the last one), and it invokes itself (i.e., AugmentStatement ) for each inner statement. For a selection statement with an else (i.e., false) branch, it creates two states, which correspond to the true and false branches. Then, it creates transitions to these states with the branch condition and its negation as guards, and invokes itself for both the true and false body statements. If the selection statement does not have an else branch, then the false branch is replaced by a simple transition to the destination state with the negation of the condition as a...