vars: {
  d2-config: {
    layout-engine: elk
    theme-id: 0
  }
}

direction: "down"

s0: {
  label: "σ₀ = {}"
}
s1: {
  label: "σ₁ = {model}"
}
s2: {
  label: "σ₂ = {model, tools}"
}
s3: {
  label: "σ₃ = {model, tools, memory}"
}
s4: {
  label: "σ₄ = {model}"
}

s0 -> s1: "neutral"
s1 -> s2: "activating"
s2 -> s3: "neutral"
s3 -> s4: "deactivating"