IS_EL_CONV : conv -> conv

- STRUCTURE
- SYNOPSIS
- Computes by inference the result of testing whether a list contains a certain element.
- DESCRIPTION
- IS_EL_CONV takes a conversion conv and a term tm in the following form:It returns the theorem
IS_EL x [x0;...xn]

if for every xi occurred in the list, conv “x = xi” returns a theorem |- P xi = F, otherwise, if for at least one xi, evaluating conv “P xi” returns the theorem |- P xi = T, then it returns the theorem|- IS_EL x [x0;...xn] = F

|- IS_EL P [x0;...xn] = T

- FAILURE
- IS_EL_CONV conv tm fails if tm is not of the form described above, or failure occurs when evaluating conv “x = xi” for some xi.
- EXAMPLE
- Evaluatingreturns the following theorem:
IS_EL_CONV bool_EQ_CONV “IS_EL T [T;F;T]”;

|- IS_EL($= T)[F;F] = F

- SEEALSO

HOL Kananaskis-14