app/views/serial_chronologies/_form.html.erb
<%= form_for(@serial_chronology) do |f| %>
<%= render 'shared/errors', object: @serial_chronology %>
<div class="field">
<%= f.label :preceding_serial_id %><br>
<%= f.number_field :preceding_serial_id %>
</div>
<div class="field">
<%= f.label :succeeding_serial_id %><br>
<%= f.number_field :succeeding_serial_id %>
</div>
<div class="actions">
<%= f.submit %>
</div>
<% end %>