import liquidjava.specification.Refinement;

public class Repro {
    private float q = 0.75f;

    public void setQ(float v) {
        this.q = v;         // any value
    }

    static void use(@Refinement("_ >= 0.0 && _ <= 1.0") float quality) {}

    void write() {
        use(q);             // accepted: q is assumed to still be 0.75
    }
}

Correct! Passed Verification.

import liquidjava.specification.Refinement;

public class Control {
    private float q = 5.0f;

    public void setQ(float v) {
        this.q = v;
    }

    static void use(@Refinement("_ >= 0.0 && _ <= 1.0") float quality) {}

    void write() {
        use(q);             // with a bad initializer: reported, so the initializer is what is assumed
    }
}

Refinement Error: quality² == 5.0 is not a subtype of quality² >= 0.0 && quality² <= 1.0
11 | 
12 |     void write() {
13 |         use(q);             // with a bad initializer: reported, so the initializer is what is assumed
   |         ^^^^^^^
14 |     }