Numeric math builtins

[aallan]

Add built-in numeric math operations. Currently Vera has arithmetic operators (+, -, *, /, %) and comparison operators but no math utility functions.

Proposed functions

Integer math

• abs(@Int -> @Nat) — absolute value
• min(@Int, @Int -> @Int) — minimum of two values
• max(@Int, @Int -> @Int) — maximum of two values

Float math

• floor(@Float64 -> @Int) — floor to integer
• ceil(@Float64 -> @Int) — ceiling to integer
• round(@Float64 -> @Int) — round to nearest integer
• sqrt(@Float64 -> @Float64) — square root
• pow(@Float64, @Float64 -> @Float64) — exponentiation

Implementation notes

All are pure functions. Most map directly to WASM instructions:

• abs: compare + negate
• min/max: i64.lt_s + select
• floor/ceil/round: f64.floor/f64.ceil/f64.nearest + i64.trunc_f64_s
• sqrt: f64.sqrt
• pow: requires a loop or import (no native WASM instruction)

These are quick wins — most are 5-10 lines of WAT each.

Dependencies

• None

[aallan]

Implemented in PR #250. Eight new pure built-in functions: abs, min, max, floor, ceil, round, sqrt, pow. Full compiler pipeline support (type registration, WASM codegen, type inference, Z3 translations for integer builtins). 46 new tests, new conformance test ch09_numeric_builtins, spec Section 9.6.3, and documentation updates across all project files.